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Question

meibomian gland neoplasia

Answer 1

Definition: are sebaceous glands at the eyelid margins Macro: well demarcated, nodular masses on the eyelid margins Micro: well differentiated enlarged lobules of sebaceous glands with variable proportion of reserve and mature sebaceous cells

Answer 2

Cause: autosomal recessive inheritance, structural defect in flagellum of spermatozoa Consequence: immotile/hypomotile spermatozoa, female infertility due to defective function of cilia in uterine tubes, oligospermia/azoospermia, also affects nasal and bronchial mucosa, affects ependyma so can cause hydrocephalus

Answer 3

Feline diffuse iris melanoma, feline post traumatic ocular sarcoma, equine intraocular melanocytic neoplasia, canine uveal melanocytic neoplasia, iridociliary adenoma and meibomian gland adenoma

Answer 4

Definition: Increase in bone density due to a failure in bone resorption by osteoclasts Affects: Different animal species Cause: Mutation that impairs generation or function of osteoclasts; viral infections (BVD) Macro: Spicules of bone fill the medullary cavity Micro: dense and irregular bony trabeculae

Answer 5

Definition: Inherited connective tissue disorder Cause: mutations in collagen 1 gene Affects: Calves, lambs, kittens, puppies and mice Macro: bones are fragile and break easily, blue sclera and fragile (pink) teeth, joint laxity Micro: reduced trabecular bone, evidence of fractures and delay in compaction of cortical bone Consequence: bone fractures and joint laxity, defective dentin and fragile teeth, blue sclera

Answer 6

Definition: focal or multifocal growth cartilage retention due to the inability to become mineralised and replaced by bone Affects: young animals, pigs, dogs, horses, cattle and poultry Cause: unknown (genetics, trauma, rapid growth, vascular factors) Macro: Flat, smooth nodule of avascular bone with overlying articular cartilage and layer of fibrocartilage is usually present on bony surface Micro: articular cartilage often with calcification, disorganised dentin Latens: well-demarcated area of necrosis of epiphyseal cartilage, centred around necrotic blood vessels and only visible microscopically Manifesta: when centre of ossification reaches area of necrosis there’s failure of endochondral ossification and retained necrotic epiphyseal cartilages is grossly visible

Answer 7

Definition: group of skeletal disorders that are characterised by loss of bone mass (osteopenia), pain and fractures in bones. Affects: numerous Cause: lack of physical exercise, malnutrition, hyperadrenocorticism, prolonged use of corticosteroids Pathogenesis: Imbalance between bone resorption and bone formation Macro: vertical trabeculae in spine Micro: Bone cortices are thin and porous, bone trabecular reduced in number and size Consequence: pain and fractures

Answer 8

Definition: Young animals (rickets) and older animals (osteomalacia), bone pain Affects: swine, cattle, goat, sheep (?) Cause: Vit D deficiency and phosphorus Pathogenesis: Rickets – osteoid gets formed but there’s no mineral to get deposited on, osteomalacia – osteoid gets laid down but doesn’t mineralise Macro: Enlarged and widened growth plates, cortical bone soft and deformed Micro: disorganised bone trabeculae and mineralised bone is irregular Consequence: bone pain, pathologic fractures and deformities

Answer 9

Definition: malignant neoplasms, cell of origin unknown. Affects: common in cats and dogs, rare in other domestic animals (older and giant dogs) Pathogenesis: • Metaphysis of long bones • Growth = rapid, aggressive, locally invasive and painful • Classified: simple, compound or pleomorphic • Site of origin: central, juxtacortical or periosteal Macro: grey/white, containing variable amounts of mineralised bone, random areas of haemorrhage

Answer 10

Affects: Large breed dogs Cause: Gradual deformation of the hip joints after birth Pathogenesis: gentle mechanical forces when persistently applied, may lead to progressive deformation of the normal bone structure. Conformation and inadequate muscle strength, produce biomechanical forces that induce slippage of the femoral head out of the acetabulum, eventually resulting in DJD

Answer 11

Definition: inflammation of joint cartilage and synovial membrane Cause: immune-mediated, idiopathic, bacteria, mycoplasma and viruses Pathogenesis: small animals usually infected via penetrating wounds and is monoarticular. Large animals usually infected hematogenously and is polyarticular

Answer 12

* Diffuse opacity of the cornea is a consequence of hyperplasia and keratinisation of the corneal epithelium * Dry conditions led to adaptive changes of the corneal epithelium

Answer 13

* Most common in cats, +/- horses * Macro: white to pink mass that outgrows from lateral limbus * Micro: eosinophils always present, but other inflammatory cells also present

Answer 14

• Clinically and histologically – superficial stromal

Answer 15

Definition: incomplete descent of testis Affects: dog, horse, boar, ram Cause: exposure to oestrogen-like compounds, failure of normal production of testosterone, failure of regulation by 1 or more genes for production of testosterone or androgen receptor Location: anywhere from caudal to kidney to inguinal ring but usually in the abdomen by the inguinal ring Macro: testis is small and fibrotic Micro: has interstitial collagen deposition, hyaline thickening of tubular basement membrane, degeneration of germinal epithelium Consequence: cryptorchid testis more prone to neoplasia

Answer 16

Definition: tubules are reduced and interstitium appears to be increased Cause: inadequate diet, endocrine abnormalities and cytogenic abnormalities

Answer 17

Affects: bull, stallion Cause: unknown (infectious = brucella) Types: interstitial, suppurative, necrotising and granulomatous Micro: lymphocytes between tubes and perivascular

Answer 18

Definition: germ cell neoplasia Affects: most common in aged stallion and second most common in canine Macro: homogenous, white or pink-grey and firm, bulges on cut section, fine fibrous trabeculae Micro: intratubular or diffuse, neoplastic cells – large, round, scant cytoplasm, large nucleus, prominent nucleolus

Answer 19

Definition: interstitial endocrine cell neoplasm Affects: dog, bull and stallion Macro: bronze-orange colour, visible bleeding; round and well-circumscribed, sometimes secretes hormones including oestrogens Micro: large round, polyhedric to spindle cell with abundant and vacuolated cytoplasm containing brown pigment’ visible necrosis and bleeding but isn’t invasive and is encapsulated

Answer 20

Definition: third most common in dog Macro: circumscribed, expansile, firm, white, lobulated (fibrous bands), enlargement Micro: abundant fibrous tissue, intratubular/diffuse arrangement of Sertoli cells

Answer 21

Definition: acute and chronic, focal, multifocal and diffuse Cause: non-infectious (traumas, congenital and acquired obstructions), infectious (brucella ovis/canis) Micro: large number of lymphocytes and plasma cells in interstitium

Answer 22

Definition: Affects: dogs most frequent Cause: brucella canis, E.coli, proteus vulgaris, strep, staph Pathogenesis: catarrhalis acinar inflammation  spreading to the interstitium  formation of the abscess  replacement of the abscess by the connective tissue

Answer 23

Affects: dogs and cats, large animals Cause: virus (eg foot and mouth), rhabdoviridae Pathogenesis: epithelial damage  intracellular edema  cell lysis  vesicle/bulla  rupture  erosions/ ulcers  cellular infiltration  scab/granulation tissue Macro: ulcers or scab

Answer 24

Definition: typically, a transient disease of pigs Cause: picornaviridae Pathogenesis: transmitted by direct or indirect contact  via oral route or through skin abrasions Macro: vesicular lesions on the feet

Answer 25

Cause: BVD, MCF, blue tongue, feline calicivirus Pathogenesis: epithelial necrosis and inflammation without vesiculation, in squamous epithelium of mouth

Answer 26

* Calf diphtheria – fusobacterium necrophorum – causes oral necrobacillosis, ulcers are covered by yellow/grey pseudo membranes * Wooden tongue – actinobacillosis lignieressi – causes granulomatous glossitis – loss of tongue muscle and its replacement with fibrous tissue during healing * Eosinophilic stomatitis – mostly seen in cats – affects upper lip, gums, palate, tongue and pharynx. Characterised by eosinophils, flame figures and chronic inflammatory cells * Lymphoplasmacytic stomatitis – idiopathic – immune mediated in cats infected with FIV or FeLV

Answer 27

Affects: mainly young Cause: parapoxvirus Pathogenesis: epithelial degeneration, hyperplasia and inflammation  papule  ulceration and slow healing Macro: pa-pules are elevated, dome-shaped or flat-topped lesions Micro: epithelial degeneration, hyperplasia and inflammation

Answer 28

Definition: highly contagious, high morbidity, low mortality Affects: ruminants and pigs Cause: picornavirus Pathogenesis: viral ingestion or inhalation  pharynx  viremia  epidermis  lesions in sites subjected to mechanical injury Macro: scab on oral mucosa, feet and teats Micro: inflammatory cells

Answer 29

Definition: wart Affects: young dogs, calves and foals Macro: pedunculated, papilliform or cauliflower – like masses

Answer 30

Definition: dilation due to insufficient/absent/uncoordinated peristalsis Cause: innervation or denervation disorders, physical obstruction Congenital: dogs, dilated portion is cranial to the heart is due to persistent right 4th aortic arch, hereditary in GSD, irish setters and grey hound Acquired: idiopathic, muscle disease (myasthenia gravis, hypothyroidism) Macro: regurgitation Micro: no microscopic lesions

Answer 31

Definition: over distension of the rumen and reticulum with gases of fermentation Primary: known as legume bloat, dietary bloat or frothy Secondary: physical obstruction or stenosis of the oesophagus (due to tumours, foreign bodies) Affects: ruminants Pathogenesis: legumes  release of chloroplast particles  rumen microbes colonise particles and degrade proteins  gas bubbles get trapped among the particles and do not coalesce  stable foam. Organic acids (from legumes) + salivary bicarbonates  CO2, blockage of cardia, increased intra-abdo pressure and death Macro: abdominal distension, animal found dead and rolled on back, bloat line Micro:

Answer 32

Definition: hardware disease Affects: ruminants Cause: Pathogenesis: sharp foreign bodies accumulate in the reticulum  penetrate reticular wall  peritonitis  penetrate diaphragm and enter pericardium  pericarditis. Affected serosal surfaces thickened by white fibrous tissue that enclose an accumulation of fibrinous and purulent exudate

Answer 33

Definition: extension from oral and oesophageal infections Affects: cattle Cause: Pathogenesis: sudden change to high easily fermentable diet  overgrowth of gram + bacterial  increased lactic and dissociated fatty acids  pH <5 and ruminal atony Macro: hyperaemia, erosion, Micro: cellular infiltration and vesiculation of the mucosa Sequelae: bacterial rumenitis, liver abscesses, mycotic rumenitis

Answer 34

Affects: large dog breeds, rarely pigs, great Dane, German Shepard Cause: failure of eructation and pyloric outflow Pathogenesis: excessive gas/ functional obstruction of cardia and pylorus  dilation  rotation on its mesenteric axis (volvulus)  compression of diaphragm, vena cava and portal vein  venous return  decreased cardiac output and perfusion to abdo viscera  shock Macro: severe abdo distension, rotation of ventrodorsally axis (180-360), haemorrhagic infarction, rupture of stomach, congestion of intestines Micro: mucosal degeneration Consequence: stomach rupture and death

Answer 35

Definition: imbalance between acid secretion and mucosal protection (gastric mucosal barrier) Cause: local mucosal injury, high gastric acidity, local ischemia, steroids and NSAIDs (Vit E deficiency) Pathogenesis: epithelial necrosis  erosion  ulceration  bleeding  perforation  peritonitis Macro: single, round or oval, sometimes elongated, it looks “punched” out Micro: muscle wall replaced with fibrous tissue, granulation tissue

Answer 36

Definition: inflammation of the stomach Affects: all Cause: cattle (c. septicum, c. perfringens), cats and dogs is by uraemia, parasitic reaction and helicobacter, pigs = sepsis due to colibacillosis or salmonellosis Pathogenesis: Macro: loss of gastric glands Micro: loss of epithelium, scattered neutrophils and haemorrhage in mucosa

Answer 37

Definition: reduction/absence of ganglion cells of myenteric plexus Cause: congenital or aquired Congenital: in pigs, dogs, foals and humans. Developmental lack of myenteric plexuses so there’s a failure of migration of neuroblasts from neural crests to colorectal myenteric plexuses Acquired: secondary to damage to colonic innervation – usually traumatic – dog hit by car

Answer 38

Definition: results in death from toxaemia, shock and starvation Cause: congenital anomaly Macro: distended abdomen, dilated bowel proximal to obstruction, collapsed and empty distal part, congested/infarcted area of obstruction

Answer 39

Definition: one segment becomes telescoped into the distal segment Pathogenesis: vascular strangulation  congestion/edema  ischemia  infarction  gangrene Macro: irritability or hypermotility, edema and ischemia

Answer 40

Definition: displacement through a foramen Internal: foramen epiploicum, omental or mesenteric tears and renosplenic ligament External: diaphragmatic, ventral, umbilical and scrotal/femoral Sequelae: incarceration, strangulation, perforation, adynamic ileus

Answer 41

Definition: secretion of abnormally fluid faeces accompanied by an increased volume of faeces and an increased frequency of defecation Affects: Malabsorption: defective digestion/absorption  stools with increased osmolarity Osmotic: exerted by luminal solutes Hypersecretion: excessive intestinal fluid secretion induced by enterotoxins Exudation: increased capillary or epithelial permeability Deranged motility: intestinal hypermotility  decreased intestinal transit time  malabsorption, decreased motility  increased intestinal transit time  bacterial overgrowth  malabsorption Pathogenesis: bacterial overgrowth  malabsorption  diarrhoea

Answer 42

Affects: most common in young animals Cause: rotavirus, coronavirus, parvovirus, pestivirus Examples: BDV, malignant catarrhal fever, transmissible gastroenteritis, porcine rotavirus enteritis

Answer 43

Definition: mucosal disease Affects: young calves Cause: pestivirus, BVDV1 and BVDV2 Pathogenesis: cytopathic (CP) and noncytopathic (NCP) biotypes. Transmission: inhalation, ingestion, transplacental and vaccination 1. If NCP crosses placental barrier during first 4 months of gestation  may result in fetal resorption, mummification, abortion and congenital anomalies 2. If calf survives  persistently infected (PI) calf  they shed the virus 3. They become exposed to CP  develop mucosal disease Macro: ulcerative esophagitis, lameness, ulcerations in mucosa of the cecum, sharply demarcated ulcers in tongue, palate, oesophagus Micro: foci of necrosis in epithelium over GALT, ulcers, lympholysis Consequence: more susceptible to mannheimiosis, chronic pneumonia and polyarhritis

Answer 44

Definition: infectious systemic disease Cause: gamma-herpes virus Pathogenesis: mechanism of injury  dysfunction and lysis of vascular endothelial cells and hyperplasia, dysfunction and lysis of lymphocytes in lymphoid tissues  virus – ingestion or inhalation  mucosa – sub/mucosal lymphoid tissue  infect lymphocytes  leukocyte trafficking to regional lymph nodes Macro: erosion/ ulceration of mucosae, CNS signs, eye lesions and lymphadenopathy, alopecia Micro: accumulation of lymphocytes Consequence: fatal

Answer 45

Definition: high mortality and high morbidity Affects: porcine less than 2 weeks old Cause: coronavirus, rotavirus Pathogenesis: feco-oral infection  viral replication  necrosis and sloughing of enterocytes  release of viral particles  extensive loss of enterocytes  villous atrophy  impaired digestion and absorption  diarrhoea Macro: dehydration, diarrhoea, small intestine is thin, indigestive milk Micro: villous atrophy, proliferation of crypts

Answer 46

Definition: also, feline parvovirus enteritis in cats Affects: feline, racoons, minks Cause: feline parvovirus enteritis Intestinal lesions: segmental, crypt necrosis and loss, intranuclear inclusions Pathogenesis: divides in intestine, bone marrow and lymphoid organs Macro: segmental, crypt necrosis Micro: villous atrophy, intranuclear inclusions, crypt squamous metaplasia and hyperplasia, lymphoid necrosis

Answer 47

Affects: canine and feline – death by endotoxemia shock Cause: parvovirus Pathogenesis: virus replicates in lymphoid tissue  cause lymphoid depletion  crypt cell destruction Macro: hyperaemic intestine with serositis, SI maybe fluid-filled and haemorrhagic Micro: basophilic intranuclear inclusion bodies In enterocytes, necrosis of crypt epithelial cells, permanent villous distortion and atrophy

Answer 48

Definition: common disease of new-born Predisposing factors: heavily contaminated environment, failure to receive colostrum, milk substitutes, cold stress, overcrowding and concurrent infections Cause: E.coli Forms: enterotoxic colibacillosis, postweaning colibacillosis, septicaemic and edema disease Pathogenesis: toxins induce hypersecretion of Cl- and reduce the absorption of NaCl and water  massive loss of water in the gut lumen  diarrhoea, dehydration and metabolic acidosis Macro: dehydration, diarrhoea, rough hair coat, serous atrophy of fat, petechial haemorrhages on tongue, gingivitis Micro: infiltration of lymphocytes and macrophages

Answer 49

Definition: enterotoxemic colibacillosis, disorder of rapidly growing healthy feeder pigs being fed a high ration diet Affects: 6-14 weeks old, dietary changes Cause: angiotoxin absorbed from intestines, E.coli Pathogenesis: dietary changes  intestine absorbs angiotoxin  fibrinoid necrosis of arteries/arterioles  generalised edema  cerebral edema Macro: generalised edema, cerebral edema Micro: fibrinoid necrosis of arteries/arterioles, swine cerebral angiopathy Consequence: most 4-8 weeks die within 48hr and neurological signs without diarrhoea

Answer 50

Definition: zoonosis Affects: humans, poultry and swine Cause: salmonella Pathogenesis: feco-oral route of transmission  organisms invade enterocytes and macrophages  enteritis, septicaemia and endotoxemia Peracute/septicaemic: S. cholerasuis, widespread petechial haemorrhages Acute: fibrinonecrotic enterocolitis, necrosis of Peyer’s patches and mesenteric lymphadenopathy Chronic: vasculitis  thrombosis  infarct  button ulcers Macro: button ulcers, fibrinonecrotic enterocolitis Micro: necrosis of peyer’s patches

Answer 51

Affects: sudden death in well-nourished animals Cause: • alpha toxin: haemorrhagic/necrotic enteritis and abomasitis (horse and rabbits), colitis X in horse • alpha, beta, epsilon: lamb dysentery • alpha, beta: bloody diarrhoea in neonates, struck in adults • alpha, epsilon: pulpy kidney disease in lambs and encephalomalacia • alpha-1: enteritis in lagomorphs: enterotoxaemia in ruminants Pathogenesis: diet change  rapid growth of clostridial organisms  angiotoxin  endothelial damage  haemorrhages, encephalomalacia and nephrosis  rapid death Macro: soft, dark-red kidney, pericardial effusion, Micro: gram positive bacilli in intestinal mucosa

Answer 52

Definition: paratuberculosis Affects: ruminants Cause: mycobacterium avium ssp. Paratuberculosis Pathogenesis: oral and transplacental transmission Macro: lepromatous form – prominent mucosal folds (cattle), tuberculoid form – caseating granulomas (sheep, goat and deer) Micro: thickening of ileal mucosa

Answer 53

Affects: pigs > 4 weeks Cause: Lawsonia intracellularis Pathogenesis: affects ileum, has low morbidity and high mortality Macro: mucosa is partially covered by yellow fibrinonecrotic pseudo membrane, large fibrinous cast is present in the lumen Micro: hyperplasia of crypt epithelium, resulting in necrosis of the crypt

Answer 54

Definition: high morbidity and 30% mortality Affects: pigs Cause: brachyspira hyodysenteriae and anaerobic bacteria Pathogenesis: Macro: haemorrhage, colonic malabsorption syndrome, bloody faeces Micro: necrosis of superficial mucosa and luminal spirochetes

Answer 55

Definition: inflammatory bowel disease Affects: dogs and cats Cause: immune mediated, parasite of dietary hypersensitivity Macro: vomiting, diarrhoea and weight loss Micro: villus atrophy, epithelial necrosis, crypt illation

Answer 56

Definition: mechanism involved in the development of neuronal necrosis Cause: trauma, compression and crushing Pathogenesis: 1. Initial injury 2. Persistent activation of glutamine receptor of affected neurone 3. Influx of extracellular Ca2+ ion 4. Impaired mitochondrial functioning and development of ROS 5. Damage to lipid membranes of nerve

Answer 57

Definition: changes occurring in nerve after axon transection/breakdown in PNS and CNS Cause: nerve stretching injury and intoxication Pathogenesis: • Changes proximal to the site of injury: central chromatolysis • Changes distal from injury site: Wallerian degeneration (axonal swelling and fragmentation of myelin- degeneration)

Answer 58

Definition: necrosis due to arteriolar obstruction Cause: • Interrupted circulation in the brain • Sudden hypotension • Drop in oxygen concentration in the inhaled air • Methemoglobinemia • Cyanide intoxication Macro: liquefactive necrosis, grey substance infarction = haemorrhagic, white substance infarction = pale (ischemic)

Answer 59

Definition: elevated intracranial pressure due to some trauma Types: • Cytotoxic: cell swelling with normal blood vessel permeability • Vasogenic: tissue swelling due to increase of extracellular fluid volume • Hydrostatic- interstitial: increase of CSF volume and leaking of CFS through ependymal layer • Hypo-osmotic: irregular ion concentration and distribution into the blood and nerve tissue Vasogenic: • Consequence of inflammation, hematoma, contusion, neoplasia, infarction • Breakdown of haematoencephalic barriers  plasma and electrolyte entering the perivascular and extracellular brain space Cytotoxic: • Hydropic degeneration of the CNS cells – intracellular fluid accumulation • evenly affects white and grey matter • Swelling develops several seconds after injury  disruption of Na/K pump  water and sodium  reducing volume of extracellular fluid and increasing ion concentration --. Transfer of capillary fluid and CSL  into the extracellular space of the cells

Answer 60

Definition: small, undeveloped cerebellum Affects: kittens, calves, piglets Cause: primarily due to intrauterine viral infections, parvovirus or pestivirus Pathogenesis: infiltrate and destroy undifferentiated cells of the outer granular layer in intensive replication that should migrate and build an inner granular layer Macro: size of cerebellum is reduced Micro: loss of outer granular layer, loss of purkinje cells, malposition of purkinje cells, edema and bleeding in the white matter, focal cavitation and white matter atrophy and lymphocytic leptomeningitis Consequence: may be incompatible with life depending on severity of hypoplasia

Answer 61

Definition: abnormal accumulation of CSF in brain cavities (ventricular and subarachnoid space) Affects: brachycephalic of miniature breeds, first 3 months of life Types: Noncommunicating congenital hydrocephalus: • Obstruction within system in rostral/lateral opening of 4th ventricle Communicating congenital hydrocephalus • Rare, communication between ventricular and subarachnoid space, blood pressure increase • Aetiology: arteritis, subarachnoid bleeding and meningitis Compensating congenital • Occurs secondary due to loss/lack of brain tissue, as part of the progression of hydrocephaly Uncommunicating acquired hydrocephalus: • Injuries of ependyma of obstruction, there’s no change in skull bones • Aetiology: compression of abscesses and neoplasm, blockage of fluids Compensating acquired hydrocephalus: • Secondary after losing of neural tissue, uni/bilateral • Consequently to: brain infarction or brain aging

Answer 62

Cause: blockage of: interventricular foramen, mesencephalic duct, lateral openings of the 4th ventricle Pathogenesis: 1. Due to non-absorption, CSL pressure in brain ventricles increases 2. Ventricles widen, ependyma is multifocally disrupted 3. CSL compress periventricular white matter 4. Hydrostatic edema of the white matter 5. Degeneration and atrophy of myelin and axons 6. Loss of tissue 7. Expansion of the ventricles Macro: thin bones, enlargement of cranium, thinning of white matter Micro: atrophied ependyma, loss of cells in white matter

Answer 63

Definition: relatively uncommon Cause: white (Escherichia, klebsiella), yellow (strep, staph), pseudomonas Pathogenesis: Macro: abscess single or multiple, discrete or coalescing

Answer 64

Affects: Cattle Cause: histophilus somni Pathogenesis: 1. Bacteria binds to endothelial cells 2. Contraction and desquamation of vascular endothelial cells 3. Vasculitis 4. Thrombosis 5. Infarcts 6. Additional bacterial multiplication in infarct tissue 7. inflammation Macro: irregular, small to large foci of bleeding and necrosis, randomly scattered on the surface of the brain and most common – cerebrum, causes septicaemia Micro: vasculitis and perivasculitis, vascular necrosis

Answer 65

Definition: bacterial disease with particular affinity for the CNS Affects: domestic ruminants Cause: poor silage, L. monocytogenes Pathogenesis: phospholipase and hemolysine 1. oral mucosa  invasion of sensory and motor branches of n. trigeminus 2. migration via sensory axons to trigeminal ganglion/brain-spinal cord 3. migration to motor axons – directly to midbrain, spinal cord 4. rostral and caudal extension of bacteria in the brain Macro: usually negative, sometimes: opacity of the leptomeninges, focal necrosis, opaque CSF Micro: neutrophils, macrophage foci, leptomeningitis, vasculitis Types: meningoencephalitis, abortions- stillbirth and septicaemia

Answer 66

Cause: Lyssavirus fam. Rhabdoviridae Pathogenesis: 1. initial replication 2. entry into the nerve through nicotine and acetylcholine receptors 3. retrograde axonal transport – to the dorsal root ganglion to the spinal cord 4. travels to the brain with ascending and descending tracts 5. infects the brain and spreads among neurones through antegrade axonal transport 6. infects the eye and salivary glands (secreted by saliva) • centripetal spreading is towards the brain and centrifugal spread away from brain Macro: most often not found Micro: lymphomonocytic meningoencephalitis, Negri bodies, spongiform lesions in grey matter Stages: prodromal (2-3 days, changes in temperament), excitatory and paralytic Types: furious (excitatory stage dominates) and dumb (excitatory stage is short)

Answer 67

Affects: Cause: Morbillivirus, fam paramyxoviridae Pathogenesis: aerosol with virus  upper respiratory tract infection  local mucosal invades macrophages  regional lymph nodes  replication within regional LN and causes viremia  infects almost all cells of the body, particularly epithelial cells and brain  decreases immune response, decreases cytokine production and predisposes for secondary bacterial infection Macro: white matter softening, diffuse interstitial pneumonia, pneumocyte type 2 hyperplasia Micro: demyelination, status spongiosus, intracytoplasmic and intranuclear primarily in astrocytes Consequence: secondary bacterial infection, hyperkeratosis of nose and foot pads

Answer 68

Affects: Feline Cause: feline enteric coronavirus which mutates to FIP virus Types: • strong cell-mediated immunity  resistance to virus, so no disease • partial cell-mediated immunity  dry (noneffusive) form (leptomeningitis) • absence of cell-mediated immunity, just humoral immunity  wet (effusive) form (serositis, accumulation of modified transudate) Pathogenesis: cats ingest the virus through contact with virus contaminated faeces or with carrier cats  feline enteric coronavirus replicates in enterocytes and causes diarrhoea or is asymptomatic  virus mutates, replicates in macrophages and causes systemic infection Macro: pyogranulomatous inflammation  vascular necrosis  infarcts Micro: granulomas and phlebitis Consequence: granulomatous pneumonia, pyogranulomatous interstitial nephritis and vasculitis

Answer 69

Definition: sporadic highly fatal viral disease Affects: cattle and other ruminants Cause: ovine herpesvirus 2, caprine herpesvirus 1,2 Pathogenesis: Macro: necrotising vasculitis, hyperaemia and cloudiness of the leptomeninges Micro: nonsuppurative meningoencephalomyelitis and vasculitis, lymphocytic perivascular accumulation and necrotising vasculitis leptomeninges and brain

Answer 70

Definition: Aujesky’s disease “mad itch” Affects: pigs primarily, domestic mammals  severe, frequently fatal (piglets can die, mature pigs remain latent carriers) Cause: pseudorabies virus (suid herpesvirus 1) Pathogenesis: enters into upper respiratory tract, tonsils and local LN  enters the sensory nerve ends  transports to the trigeminal ganglia and bulbus olfactorious  brain. Glycoproteins on the surface of the virus allow binding and entry into the cell Macro: leptomeningeal congestion Micro: nonpurulent meningoencephalomyelitis, intranuclear eosinophilic inclusions and degeneration and necrosis

Answer 71

Definition: distinct viral strain of the ovine maedia-visna virus - lentivirus Pathogenesis: immune reactions of macrophages and lymphocytes  cytokines, other inflammatory mediators  neuronal and oligodendroglia damage (initial stage)  demyelinisation  due to oligodendroglia cell infection (later phase) Macro: yellowish-creamy areas on the cross section Micro: nonpurulent encephalomyelitis, pleocytosis and edema

Answer 72

Affects: cat, dog, horse and cattle Cause: FIV, FeLV, ehrlichia canis, C neoformans and C gattii Pathogenesis: direct spread after sinus or nasal infection within macrophages Macro: within CNS and leptomeninges – multiple small cysts of gelatinous appearance Micro: multicellular-monocellular fungi, without inflammatory reactions, with mild/moderate infiltration of neutrophils, eosinohpils

Answer 73

Affects: cats Cause: toxoplasma gondii Pathogenesis: infection and destruction of endothelial cells by tahizosis  vasculitis  haemorrhagic infarcts, edema Macro: acute: bleeding, necrosis, chronic: yellow-brown, necrotic foci Micro: • acute: swelling of endothelial cells, infarctions, edema, • subacute: necrosis and bleeding often of extensive lymphocytic and macrophage pervascular infiltrates • chronic: cysts with bradyzoits Consequence: abortion

Answer 74

Affects: dog, cat, cattle and sheep, horse Cause: neospora caninum Macro: foci of haemorrhage and necrosis distributed

Answer 75

Cause: lack of thiamine Macro: brain swelling, yellowish discolouration, edema and prominent areas of atrophy Micro: laminar cortical necrosis and astrocyte swelling, monocyte infiltration and phagocytosis of cellular debris

Answer 76

Definition: pulpy kidney disease, overeating disease Affects: sheep goat and cattle Cause: epsilon toxin Pathogenesis: vascular injury and failure of haematoencephalic barrier  binding of epsilon toxins to endothelial cells  opening of tight junctions  increase of vascular permeability  vasogenic edema  swelling of astrocytic processes  necrosis Macro: bilaterally symmetrical foci of encephalomalacia, extra neural changes Micro: vasogenic edema, hyalinisation of capillary walls and endothelial cells swelling

Answer 77

Definition: classified according to degree of differentiation Affects: dogs (5-11yrs) brachiocephalic breeds, rarely cats Cause: degree of malignancy is inversely proportional to the degree of differentiation Macro: compressive atrophy of the surrounding tissue, well differentiated Micro: tumour cells are arranged around the blood vessels

Answer 78

Definition: most common neuroectodermal neoplasia of the CNS, affect the white matter of cerebrum Affects: most common In dogs 5-11yrs (brachiocephalic breeds), cats and cattle Macro: well restricted, grey/pink, soft creamy with bleeding areas Micro: highly cellular, expressed nucleus, pale or translucent cytoplasm

Answer 79

Definition: most common mesodermal neoplasm of CNS, originate from arachnoidal cap cells Affects: older cats, especially over 10 yr, dogs 7-14 yrs Located: in 3rd ventricle, surface of the brain and at base of the brain Macro: compressive atrophy Micro: form a vortex layer configuration, grouped to: epithelial, fibroblastic, transitional, psammomatous, angioblastic and anaplastic

Answer 80

Definition: disease that affects the postganglionic sympathetic and parasympathetic neurones Affects: horse Cause: ingestion of food contaminated with toxin of the Cl. botulinum Pathogenesis: Macro: no macroscopic changes on PNS Micro: chromatolysis, degeneration – neurones of autonomic and enteric ganglia within the ileum

Answer 81

Definition: disorder of neuromuscular impulse transmission Inherited: too small number of acetylcholine receptors on the muscular plates of neuromuscular joints Acquired: thymoma, development of antibodies that binds to acetylcholine receptors on postsynaptic muscle membranes Macro: skeletal muscle weakness and megaoesophagus development Micro: none

Answer 82

Definition: tumours of peripheral nerve system Affects: dogs older, cattle and cats older, in cranial nerve 5 (dogs), cattle CN 8 Macro: nodular thickening to the nervous trunk or nerve roots, soft to hard elastic, white to grey Micro: densely cellular, monomorphous spindle cells and various rich collagen stroma

Answer 83

Definition: inflammation of brain Cause: bacteria, listeria monocytogenes, Haemophilus, virus, mycoplasma Macro: congestion, haemorrhage, tiny abscess Micro: necrosis of neurons, infiltration by neutrophils and lymphocytes

Answer 84

Definition: inflammation of meninges Cause: virus, trauma, bacteria, toxoplasma, Leptospira Macro: congestion, petechial haemorrhage Micro: fibrosis, infiltration of neutrophils and lymphocytes and thickening of meninges

Answer 85

Definition: formation of large fluid filled cavities in the brain Cause: BVD, orbivirus and rift valley Pathogenesis: virus infect and destroy differentiating neuroblasts and neuroglial cells in developing foetus in utero Macro: thin-walled, fluid filled cysts in cerebral hemispheres Micro: necrosis of undifferentiated cells surrounding the fluid filled cavities Consequence: denervation atrophy of limb muscles, arthrogryposis, non-suppurative encephalitis

Answer 86

Definition: uraemia and consequences of urinary disease Affects: Cause: prerenal (decreased circulation), intrarenal (infections, toxins), postrenal (obstruction of tract) Pathogenesis: Alteration: decreased ultrafiltration, intratubular obstruction, fluid back leak and intrarenal vasoconstriction

Answer 87

Definition: replacement of renal parenchyma with mature fibrous CT Cause: infarction, glomerulonephritis and tubulointerstitial disease Pathogenesis: irreversible and progressive Macro: pale, shrunken and pitted kidney Micro: increase in interstitial CT, small cysts in cortex and medulla, lymphoplasmacytic infiltrates in interstitium Consequence: fibrous osteodystrophy and renal secondary hyperparathyroidism

Answer 88

Definition: seen with severe glomerular lesions Pathogenesis: proteinuria (increased permeability), hypoproteinaemia, edema (decreased oncotic pressure), hypercholesterolemia (from protein loss)

Answer 89

Definition: altered structural organisation resulting from abnormal differentiation with presence of structures Pathogenesis: asynchronous differentiation of nephrons Macro: small and/or misshapen Micro: small hypercellular glomeruli, atypical tubular epithelium, presence of cartilaginous and/or osseous tissue

Answer 90

Definition: can be associated with renal dysplasia or can occur as primary entities Congenital: can occur as a primary entity or in cases of renal dysplasia Pathogenesis: 1. Obstruction of the nephron  elevated luminal pressure and secondary dilatation 2. Defective tubular basement membranes allow saccular dilatation of tubules 3. Derange function of renal tubular cilia  epithelial hyperplasia and production of new BM  increased tubular secretion 4. Dedifferentiation of tubular epithelium  loss of polarity of cells – abnormal cell arrangements  decreased absorption of fluid  dilation Macro: spherical, thin walls, clear watery fluid

Answer 91

Definition: have many cysts that involve numerous nephrons Affects: occur sporadically in all species and may be inherited in some pigs and lambs Cause: mutation in PKD1 and 2 Pathogenesis: mutation in PKD-1 and PKD-2 genes  altered function of related proteins  modify cilia function, cell proliferation and migration  tubular epithelial proliferation and increased fluid secretion Macro: “swiss cheese”

Answer 92

Cause: occurs in acute systemic viral disease (hog cholera, infectious canine hepatitis) Macro: swollen kidneys, smooth capsular surface, pinpoint red dots on the cut surface Micro: intranuclear inclusions in endothelial cells, endothelial hypertrophy, necrosis and haemorrhage

Answer 93

Cause: direct Injury to glomerular epithelial and endothelial cells Pathogenesis: induction of immunologic reaction and inflammatory responses  immune complexes deposition, formation of ANA-s and anti-GBM antibodies Micro: interstitial fibrosis

Answer 94

Cause: result of bacteriemia  cause multiple foci of inflammation, actinobacillosis, erysipelothrix Pathogenesis: Macro: multifocal, random, raised, 1mm foci Micro: glomerular capillaries contain numerous bacterial colonies mixed with necrotic debris and neutrophils

Answer 95

Cause: glomerular lesions is immunologic damage.. direct (antibody responding to an antigen in the glomerulus), indirect (from formation of antigen-antibody complexes) Pathogenesis: Macro: (acute) kidneys slightly swollen, smooth capsular surface, slightly pale, glomeruli. (chronic) cortex becomes shrunken, granularity of capsular surface, glomeruli – pinpoint pale grey dots Micro: • According to morphology: proliferative, membranous and membranoproliferative • According to localisation and distribution: diffuse, focal, global and segmental

Answer 96

Definition: most common cause of acute renal failure, injury resulting in the death of tubular epithelial cells Affects: Cause: heavy metals (mercury, lead), antibacterial agents (tetracyclines), NSAIDS (aspirin, naproxen), mycotoxins, plants (pigweed, yellow wood tree, easter lily), Vit D, antifreeze Pathogenesis: Macro: white to tan cortex Micro: pyknotic nuclei indicative of cell necrosis, swollen or granular cytoplasm, hyaline casts and cell death

Answer 97

Definition: form of tubular necrosis and interstitial necrosis Affects: dogs and cat Cause: NSAIDs Pathogenesis: NSAIDs interfere with production of renal prostaglandins  alteration in prostaglandins cause vasoconstriction and loss of perfusion to the distal tissues of the kidney  papilla became ischemic and then necrotic Macro: necrotic area is yellow-grey, green or pink and sloughs and is friable Micro: necrotic areas, cross section is narrowed

Answer 98

Definition: inflammation of interstitium and tubules Affects: horse, cattle, sheep, pigs and dogs Cause: H (equine viral arteritis), C (Escherichia coli septicemia), S (sheeppox), P (leptospira interrogans), dogs (infectious canine hepatitis and leptospira interrogans) Pathogenesis: Acute: interstitial infiltrates of inflammatory cells are present including neutrophils and plasma cells Chronic: progresses to interstitial fibrosis and loss of tubules Macro: swollen kidneys, cut surface bulges Micro: inflammatory cells, aggregate of lymphocytes, monocytes, plasma cells

Answer 99

Pathogenesis: leptospiremia  localisation in renal interstitial capillaries  migration through endothelium  persist in interstitium  invade tubules through lateral interstitial junctions  associate with epithelial microvilli  persist in phagosomes of epithelial cells of proximal and distal tubules  induce degeneration and necrosis of epithelium  induces interstitial inflammatory reaction

Answer 100

Definition: interstitial disease that accompanies chronic systemic disease characterised by multiple granulomas Affects: domestic animals, pig, cattle Cause: coronavirus, mycobacteria, fungi, protozoa, parasites Micro: fibrosis

Answer 101

Definition: inflammation of renal parenchyma and renal pelvis Affects: anything that predisposes the animal to UTI Cause: usually from ascending urinary tract infection, E.coli, klebsiella, staph, strep Pathogenesis: abnormal reflux of bacteria-contaminated urine from lower tract to pelvis and collecting ducts, infection ascends ureters via vesicoureteral reflux  pelvis of kidney becomes infected  bacteria gain access to renal parenchyma by collecting ducts and direct invasion across erosions in pelvic urothelium Macro: pelvis and ureter dilated, purulent exudate, papilla necrotic with haemorrhage Micro: large number of neutrophils, sloughed tubular epithelial cells, necrosis of collecting ducts Consequence: if chronic, there will be fibrosis of the kidney

Answer 102

Definition: dilation of the renal pelvis and accompanying renal atrophy Affects: all domestic animals Cause: partial or complete obstruction of urine outflow causing a progressive increase in pelvic pressure Pathogenesis: increase in intratubular pressure  glomeruli remain functional  glomerular filtrate diffuses into interstitium  intrapelvic pressure increases Macro: Micro: thin walled

Answer 103

Definition: most common primary renal neoplasia Affects: most frequent in older dogs Cause: virus, chemical carcinogens and autosomal dominant gene mutations Pathogenesis: Macro: large, typically spherical to oval and firm, on section they may be pale yellow with areas of haemorrhage and cystic degeneration, pale yellow Micro: cuboidal to columnar epithelial cells in solid sheets, tubules or papillary projects

Answer 104

Definition: nephroblastoma Affects: young animals but may not be diagnosed until they reach a very large size Cause: arises from metanephric blastema Pathogenesis: 1. Result from malignant transformation during normal nephrogenesis 2. Arise from malignant transformation in nests of embryonic tissue that persists in postnatal kidney Macro: Micro: typically, have loose myxomatous mesenchymal tissue

Answer 105

Definition: presences of stones (calculi, uroliths), in the urinary collecting system • Renal pelvis (nephroliths), ureter (ureterolith), urinary bladder (urocystolith), urethra (urethrolith) • Mini schnauzers – struvite calculi, dalmatian dogs – uric acid Consequence: predispose to infection, obstruction, haemorrhage and necrosis, cloudy urine Predisposing factors: cystitis, urine pH, reduced wate intake, Vit A deficiency, NSAIDs Cause: when familial, congenital and pathophysiological factors occur together and cause the precipitation of excretory metabolites in urine into grossly visible stones, mineral imbalance Pathogenesis: Macro: calculi, cloudy urine, haemorrhage, distension of ureters and urinary bladder, enlarged kidneys Micro: crystals, degeneration and necrosis of tubular eptihelium

Answer 106

Definition: inflammation of the urinary bladder Acute: Predisposing factor: stagnation of urine, vaginoscopy, more common in females, klebsiella Macro: haemorrhage, fibrinous and suppurative, necrotising, thickened bladder wall, cloudy urine Micro: epithelial denudation, bacterial colonies and lamina propria edema Chronic: • If bacteria isn’t destroyed the infection may persist and become chronic • The wall becomes thickened due to fibrosis • Often mucosal proliferation as well – polypoid cystitis • Hyperplasia of lymphoid nodules in lamina propria – follicular cystitis Mycotic cystitis Cause: Candida albicans, aspergillus Affects: immunosuppressed animals or subjected to prolonged antibiotic therapy Pathogenesis: mucosa is usually ulcerated with proliferation of underlying LP  accumulation of neutrophils, lymphocytes, plasma cells, macrophages  thickening of the bladder wall Toxic cystitis (brackern fern and enzootic hmaturia) Cause: plant pteridium

Answer 107

Definition: autosomal recessive mode of inheritance Affects: German shepherd, spitz, toy pinscher Cause: molecular defect in LHX3 gene-deletion in exon 5 Low GH, TSH, prolactin and gonadotropic, ACTG normal or low Pathogenesis: Macro: slower growth, retention of puppy hair coat, bilaterally symmetric alopecia, skin hyperpigmentation Consequence: slow/subnormal growth, retention of woolly puppy coat and hyperpigmentation and bilaterally symmetrical alopecia

Answer 108

Definition: adenoma of pars intermedia Affects: equine – old age Pathogenesis: compression of hypothalamus by large neoplasms  polyuria, polydipsia, muscle weakness, hyperthermia, hypertrichosis – hirsutism Cell of origin: cells that produce proopiomelanocortins (POMC) Symptoms: hypertrichosis, chronic laminitis, weight loss and abnormal distribution of fat Consequences: can compress hypothalamus so PUPD, polyphagia and hirsutism

Answer 109

Definition: cortisol excess Affects: adult and aged dogs, infrequently in cats and rare in other domestic animals Cause: functional neoplasm, ACTH-secreting adenoma of pituitary gland, iatrogenic excess of corticosteroids Pathogenesis: increased gluconeogenesis, lipogenesis and protein catabolism. Macro: increased appetite, weakened and atrophied muscles, hepatomegaly, skin lesions, pedunculus abdomen Micro: atrophy of skeletal muscles

Answer 110

Definition: adrenal cortical insufficiency Affects: young sexually mature dog Cause: autoimmune disorders Pathogenesis: Macro: decreased blood volume, pressure, hyperpigmentation Micro: lymphocytes and plasma cells are distributed diffusely throughout adrenal cortices

Answer 111

Definition: nonneoplastic and noninflammatory enlargement of the thyroid gland Cause: goitrogenic compounds, deficiency or excess of iodine, genetically determined defects Pathogenesis: Types: • Diffuse hyperplastic o Follicles irregular in size and shape o Thyroid gland enlarged and dark-red • Multifocal nodular o Usually, endocrinologically inactive • Congenital o Autosomal recessive, alteration in synthesis of thyroglobulin or thyroid peroxidase, lambs, kids, calves, dogs and cats • Colloid o Hyperplastic follicular cells continue to produce colloid but endocytosis of colloid is decreased, thyroid glands lighter in colour Micro: hyperplasia of the gland

Answer 112

Definition: excessive secretion of thyroid gland hormones Affects: cats Cause: elevated circulating T4 and T3 concentrations, tumourin thyroid Pathogenesis: purified IgG increases H-thymidine incorporation into DNA and stimulates follicular cell proliferation Macro: increased basal metabolic rate, bulging of eyeballs Micro: nodules

Answer 113

Definition: reduced secretion of thyroid hormones Affects: golden retriever, Doberman pinscher, dachshund, miniature schnauzer Cause: adult, older dogs Pathogenesis: • Decreased basal metabolic rate  gain in body weight without changes in appetite • Increased cholesterol  atherosclerosis • Thinning of hair coat and symmetric alopecia, hyperkeratosis, hyperpigmentation Macro: decreased basal metabolic rate, obesity Micro: follicles lined by low cuboidal or flattened epithelial cells

Answer 114

Definition: sensitive indicators of changes in the blood CO2, pH and oxygen tension Affects: brachycephalic breeds Cause: unknown Pathogenesis: • Carotid – near the bifurcation of carotid artery, genetic predisposition aggravated by chronic hypoxia, unilaterally and slow growing • Aortic – near the base of the heart – attached to the adventitia of the pulmonary artery, more common than carotid body and most common in boxers. Non-functional but cause heart failure due to compression, solitary mass or multiple nodules Macro: neoplastic tissue is lobulated by fibrous trabeculae Micro: neoplastic cells are aligned along small vessels and are round to polyhedral and closely paced with pale eosinophilic, finely granular

Answer 115

Definition: rare, autosomal recessive defect in lysosomal trafficking regulator Affects: cattle, persian cats, orca, mice and humans Problems: severly impaired innate immunity due to neutropenia, impaired leukocyte chemotaxis, tendency to bleed and prone to infection Macro: oculocutaneous albinism due to altered distribution of melanin granules Micro: giant granules in phagocytic cells and melanocytes

Answer 116

Definition: sensitivity to ischemia: myofibers > satellite cells >fibroblasts Affects: cow, horse Cause: external pressure on the muscle by objects, compartment syndrome and vasculitis Pathogenesis: increased intramuscular pressure during prolonged periods of recumbency  compression to arteries  decreased blood flow Macro: areas of muscle pallor, haemorrhage may occur particularly with compartment syndrome Micro: myofiber coagulative necrosis, sometimes accompanied by haemorrhage

Answer 117

Definition: extensive coagulative necrosis of muscles Affects: horse, cattle, sheep and goats Cause: deficiency of Vit E and selenium, stress Pathogenesis: Macro: marked by mineralisation of skeletal and/or cardiac muscle, pale sometimes white streaks and maybe gritty when cut, becomes pale pink, yellowish red, grey or white. Becomes dry, inelastic and firm Micro: early lesions are characterised by rounded, large, hyalinised myofibers with or without fragmentation

Answer 118

Definition: equine rhabdomyolysis Affects: riding and racing horses Cause: following exertion, usually, brief rest results in recovery with few consequences, accumulation of lactate, lack of oxygen and high glycogen store Pathogenesis: changes are thought to involve the strongly glycoltic type II fibres Macro: myoglobinuria, swelling of affected muscle group, increased serum CK and AST, urine is dark brown, tonic spasms, atrophy, edema Micro: same as nutritional myopathy, necrosis of muscle fibres, hyaline degeneration

Answer 119

Definition: acute, noncontagious infectious disease Affects: cattle Cause: clostridium chauvoei Pathogenesis: ingested spores are absorbed from the intestinal tract  disseminated via the bloodstream to the skeletal musculature and other tissues  remain latent but can begin to proliferate if a bruise is present  spores activate after trauma, bacteria proliferate and produce toxins  cause capillary damage, haemorrhage, edema and necrosis Macro: yellow gelatinous exudate, blood and gas bubbles are present in the subcutaneous and intermuscular CT, affected muscles are swollen, dark red to black and typically porous, spongy and dry Micro: intramuscular blood and gas bubbles separate swollen eosinophilic myofibers, myofibers are fragmented, with shredded or granular sarcoplasm and pyknotic nuclei

Answer 120

Definition: immune mediated myositis disease Cause: no specific cause, maybe ehrlichia canis Macro: pain during manipulation, elevated serum muscle enzyme Micro: focal, multifocal or diffuse necrosis, phagocytosis and lymphoplasmacytic infiltrates

Answer 121

Definition: progressive destruction of the masticatory muscles with eventual fixation of the jaw Affects: immune mediated in dogs Cause: humoral antibody response against myosin type 2, found in masticatory muscles Macro: lesions are bilaterally symmetric Micro: during acute phases there’s severe infiltrates of eosinophils and fewer lymphocytes, neutrophils and plasma cells, plasma cells are most numerous and eosinophils less common in chronic lesions during periods of quiescence

Answer 122

Definition: immune-mediated attack directed specifically at extraocular muscles Affects: golden retrievers predisposed Macro: acute onset of bilateral exophthalmos

Answer 123

Definition: porcine stress syndrome, pale soft exudative pork Affects: pig Cause: genetic defect, stress Pathogenesis: genetic defect results in abnormal activity of the skeletal muscle ryanodine receptor  uncontrolled intracytoplasmic Ca release  excessive contraction with resultant heat production Macro: affected muscle pale, soft, swollen and appears “cooked”

Answer 124

increasing of cell number

Answer 125

unnaturally large or morphologically irregular cells

Answer 126

reduced number of haemtopoietic cells

Answer 127

absence of development of certain vectors of haematopoietic blood cells

Answer 128

destruction of all three blood cell lines

Answer 129

disorder of hematopoietic stem cell clones

Answer 130

replacement of haematopoitic bone marrow tissue by abnormal tissue

Answer 131

reduced blood cell concentration of all three lines

Answer 132

Definition: reduction of erythrocyte concentration Types: Regenerative anaemia (bleeding/haemorrhage or haemolysis), nonregenerative anaemia (primary bone marrow disease and extramedullary diseases) Aplastic anaemia: cause: stem cell destruction (chemical, infectious and idiopathic)

Answer 133

Affects: cattle and cat Cause: porphyria = inherited defects of enzymes Pathogenesis: inherited defects of enzymes involved in the synthesis or porphyrin and other haemoglobin proteins  accumulation of toxic components of porphyrin  haemolytic anaemia, accumulation of pigment, photosensation of non-pigmented skin

Answer 134

Definition: intraerythorycitc protoszona organism Affects: horse, cattle, dog and cat Cause: babesia: equi, bovis, canis, cati, felis… Pathogenesis: intravascular and extravascular haemolysis due to direct or indirect damage by the parasites, immune mediated destruction  massive immunostimulation and release of cytokines causes shock and systemic inflammatory response which can lead to multiple organ failures Macro: anaemia, icterus, splenomegaly, haemoglobinuria, gallbladder filled Micro: degeneration and necrosis of centrolobular hepatocytes

Answer 135

Cause: tick borne  intralymphocytic or monocytic shizonts, intraerythrocytic pirpoalsms

Answer 136

Affects: equine Cause: EIA virus, lentivirus fam Pathogenesis: virus infects monocytes which then become macrophages  macrophrage produce inflammatory chemo+cytokines  arrival of new monocytes and lymphocytes then infected/destroyed Macro: anaemia, jaundice, hepatomegaly, splenomegaly Micro: subcapsulat bleeding, Kupfer’s cells with phagocytosed erythrocytes Consequence: acute period of fever, depress + thrombocytopenia potentially fatal but usually subsides within a year and then horse becomes lifelong carrier

Answer 137

Definition: malignant tumour of plasma cell- bone marrow origin Pathogenesis: significant increase in number of plasma cells, often found in aggregates  causing monoclonal gammopathy Micro: osteolysis, promoting survival of osteoclasts and bone destruction

Answer 138

Definition: malignant neoplasia of histiocytic origins Affects: dog breeds predisposed (bernes mountain, rottweiler)

Answer 139

Definition: inflammation of the nasal mucosa, upset in the balance of microbial flora Serous rhinitis: clinically the mildest form of inflammation, hyperaemia, serous discharge, mild irritants – cold air, viral infections, mild allergic reactions Catarrhal rhinitis: serous fluid, significant amount of mucus, thick, translucent viscous discharge, few desquamated and inflammatory cells and detritus Purulent rhinitis: severe damage, necrosis and secondary bacterial infection, characterised by purulent exudate, mucosal necrosis and bacterial infection. Macro = exudate is thick, dull green-brown in colour, blockage of the nasal passages Fibrinous rhinitis: severe damage, severely impaired vascular permeability – exudation of fibrinogen coagulating into fibrin, macro= fibrin – yellowish-brown, rubbery. Micro= perivascular edema and fibrin Granulomatous rhinitis: accumulation of mononuclear cells in the mucosa and submucosa, polypoid nodules, cause chronic allergy, infections

Answer 140

Definition: inflammation of the sinus mucosa Affects: domestic animals Pathogenesis: serous catarrhal, fibrinous, purulent or granulomatous. There’s poor drainage so exudate tends to accumulate causing mucocele

Answer 141

Affects: horse (young racehorse and weaning foals Cause: equine herpes virus EHV1,4 Pathogenesis: aerogenous Macro: bronchopneumonia, bacterial rhinitis and pharyngitis

Answer 142

Definition: highly contagious common disease Affects: horse Cause: influenza virus type A Pathogenesis: virus spreads through inhalation  multiples in respiratory epithelium Macro: conjunctivitis, rhinitis, interstitial pneumonia and edema, erosions in mucosa Micro: hyaline membrane formation on bronchiolar and alveolar epithelium

Answer 143

Definition: infectious and highly contagious Affects: horse, mostly foals and young horses Cause: strep equi Pathogenesis: susceptible horse comes into contact with feed, exudate or air droplets containing the bacterium  after penetration through nasopharyngeal mucosa  strep drains to regional lymph nodes Macro: purulent rhinitis and lymphadenitis, enlarged LN Bastard strangles: hematogenous dissemination of strep results in metastatic abscess in organs Micro: lymphoid depletion in spleen, infiltration of neutrophils, degeneration and necrosis in liver

Answer 144

Definition: zoonosis, hematogenous dissemination after p/o infection Affects: horse Cause: burkholderia mallei Pathogenesis: through ingestion of contaminated feed and water  contaminated by nasal discharge  spread also through inhalation  invades the intestinal wall  invades regional lymph nodes  proliferates at pharyngeal LN can be transmitted to carnivores but ingestion of infected horsemeat Macro: pyogranulomatous nodules in submucosa, ulcers in nasal passage, edema of LN, lymphadenitis Micro: chronic granulomas with necrotic centres, macrophage infiltration

Answer 145

Definition: mannheimia haemolytica Affects: cattle Cause: BHV-1 Pathogenesis: nasal exudate and coughed up droplets  aerosol or droplet infection  entry into respiratory system  multiples in nasal cavity and upper respiratory  loss of cilia in trachea  spreads from nasal mucosa through trigeminal ganglion  causing non-suppurative encephalitis Macro: severe hyperaemia, ulcers, pneumonia Micro: necrotic lesions, infiltration of lymphocytes, hyaline membrane pneumonia Consequence: bronchopneumonia and diphtheritic inflammation

Answer 146

Definition: porcine reproductive and respiratory syndrome Cause: arterivirus Transmission: through bodily fluid and trans placentally, Pathogenesis: virus enters via mucosa and replicates in macrophages  viremia and dissemination of macrophages to the lungs, liver and spleen Macro: haemorrhage in umbilical cord, ascites, hydrothorax, enlarged LN, rib impressions on lungs, endometritis and myometritis Micro: segmental arteritis, thickened alveolar septal walls in lung, interstitial pneumonia Consequence: late term abortion and predisposition to secondary bacterial infections

Answer 147

Definition: acute respiratory distress syndrome – lung shock Cause: sepsis, major trauma, burns, pancreatitis or aspiration of gastric content Pathogenesis: injury provokes hyperactive macrophages which triggers a cytokine storm  causes formation of free radicals and cytotoxic enzymes  causes alveolar and endothelial damage which cause lung edema Macro: pulmonary hypertension, hyaline membranes and lung edema Micro: intravascular aggregation of neutrophils and diffuse alveolar damage

Answer 148

Affects: swine Cause: combined infection – Bordetella bronchiseptica and Pasteurella Pathogenesis: cytotoxins stimulate osteoclastic bone resorption Macro: inflammation and atrophy of the nasal concha with deformation of the snout and septum Micro: osteoclastic hyperplasia

Answer 149

Affects: feline (kittens) Cause: FHV-1 frequent Pathogenesis: causes impairment of pulmonary defence predisposing cats to secondary bacterial infection  replication of virus in nasal, conjunctival, pharyngeal causes degeneration and exfoliation of cells Macro: oculonasal discharge, severe rhinitis, conjunctivitis, interstitial pneumonia Micro: ulcerative keratitis, hepatic necrosis, epithelial degeneration and desquamation

Answer 150

Definition: common disease Affects: cats Cause: calicivirus Pathogenesis: affects lining of the mouth and lungs Macro: mucopurulent conjunctivitis and rhinitis, arthritis, diffuse interstitial pneumonia and ulcers on tongue

Answer 151

Definition: aerocystitis Affects: horse Cause: fungal infection Pathogenesis: pathogens infect the diverticula Macro: guttural pouch mycosis and guttural pouch empyema Micro: severe necrotic inflammation of the mucosa and submucosa and vasculitis and necrosis of the wall

Answer 152

Definition: decreased air volume in the lungs, incomplete alveolar distension Affects: all Congenital: in new-borns that fail to inflate their lungs, caused by obstruction (aspiration), or when cannot remain distended due to alteration in quantity and quality of surfactant Acquired: compressive (pneumothorax, hydrothorax), obstructive (foreign body, inflammation, parasites), contraction (pulmonary fibrosis) Pathogenesis: Macro: dark blue-reddish colour, without air Micro: collapse of the alveoli, tissue resembles an interstitium Consequence: if congenital = brain damage due to hypoxia, surviving foals = wanderes due to lack of fear and ammbling

Answer 153

Definition: increased amount of air in the lungs Affects: secondary in domestic animals (with bronchopneumonia) Cause: alveolar destruction of the alveolar wall and formation of vesicles to bulla. Interstitial – predominantly in cattle, accumulation of air in the interstitium Pathogenesis: Macro: bronchopneumonia, bronchitis, bronchiolitis, cut surface is smooth and dry Micro: hyperplasia of lymphoid tissue, alveoli are distended

Answer 154

Hemodynamic edema: increased transudation due to: increased hydrostatic and decreased osmotic pressure. Fluid first accumulates perivascularly and then penetrates the alveoli (heart failure) Neurogenic edema: consequence of increased intracranial pressure, cause – head injury, brain tumour, bleeding in the brain Macro: lungs are moist and heavy, black red, bronchi and trachea filled with foamy fluid Micro: inflammation

Answer 155

Definition: inflammation of the bronchi Affects: Cause: Pasteurella, virus, parasites Pathogenesis: catarrhal, purulent, fibrinous and granulomatous Macro: mucous exudate in lumen, congestion Micro: hyperplasia/necrosis of bronchiolar epithelium, accumulation of mononuclear cells

Answer 156

Definition: most severe consequence of chronic obstructive bronchitis Cause: severe consequence of chronic obstructive bronchitis, secondary bacterial infections with P. multicoda, T.pyogenes, or M. haemolytica Pathogenesis: permanent dilation of bronchi due to accumulation of exudate and partial rupture of wall Macro: bacterial infection causes purulent bronchopneumonia, distinguish from an abscess macroscopically

Answer 157

Cause: viral damage, action of oxidants and ROS Pathogenesis: bronchiolar fluid becomes mucinous – cannot be removed from bronchioles  bronchiolar obstruction with consequent emphysema and atelectasis

Answer 158

Cause: consequence of allergy to dust or mould from food, unknown Macro: faint changes, mostly emphysema Micro: bronchiolitis with goblet cell metaplasia and mucus hypersecretion, small number of eosinophils, goblet cell metaplasia, mucus hypersecretion and some eosinophils

Answer 159

Definition: repeated episodes of bronchoconstriction, cough and dyspnoea Affects: feline Cause: allergy to dust, smoke, parasitic proteins Pathogenesis: type 1 hypersensitivity to inhaled allergens Macro: bacterial pneumonia, mucosal edema Micro: inflammation of the bronchioles, infiltration of leukocytes

Answer 160

Definition: inflammation affects a single layer of the alveolar wall and the adjacent bronchial interstitium Cause: aerogenic – damage to the alveolar epithelium, gases, viruses Acute: begins in the exudative phase due to damage to pneumocytes 1 and/capillary endothelium with the formation of alveolar hyaline membranes Chronic: characterised by alveolar fibrosis, accumulation of mononuclear cells in the interstitium and persistence of pneumocytes II, colour is reddish grey, rubbery in consistency and fleshy in cross-sectional appearance Pathogenesis: aerogenous injury to alveolar epithelium  inhalation of toxic gases  can damage epithelium  spores combine with antibodies and deposit antigen-antibody complexes in alveolar wall (type 3) Macro: cut surface “meaty”, lungs pale/dark red in colour Micro: thickening of alveolar septum, infiltration of mononuclear cells

Answer 161

Definition: inflammation characterise by presence of fibrin in alveoli Cause: bacteria, virus, parasites Macro: lungs deep red, surface is covered by fibrin sheet, congestion Micro: interlobular septa prominent, BALT hyperplasia, sequestration, pleural adhesion

Answer 162

Definition: bacteria in the blood Cause: trueperella pyogens, fusobacterium necrophorum, strep and staph Macro: small round foci, haemorrhagic edge (in all pulmonary lobes)

Answer 163

Definition: characterised by granuloma formation Causes: resistant to phagocytosis – granulomatous inflammation, cryptococcus neoformans Macro: pyogranulomas and calcified with dissemination of infection Micro: interstitial macrophages, lymphocytes, few neutrophils and some giant cells

Answer 164

Definition: most common type of pneumonia, affected cranioventral parts of the lungs Affects: domestic animals (most common) Cause: aerogenic infection with bacteria and mycoplasma Purulent: lobular distribution especially in cattle and pigs, lungs are hyperaemic and oedematous. Healing occurs within a month and common causes are Pasteurella multocida, Bordetella bronchiseptica Fibrinous: leads to pleuropneumonia, Causes: manheima, histophilus, mycoplasma Macro: active hyperaemia and edema, mediastinal LN swollen Micro: inflammatory exudate accumulates in the bronchi, bronchioles and alveoli, infiltration of neutrophils

Answer 165

Definition: shipping fever Affects: cattle Cause: mannheimia haemolytica – biotype A, serotype 1 Pathogenesis: bacteria releases toxins (endotoxin, lipopolysaccharides, adhesion, leucotoxin) which kills macrophages and neutrophils these release TNF-alpha, IL1 and 8, histamine  necrosis of alveolar and bronchial epithelium Macro: severe fibrinous bronchopneumonia, fibrinous pleuritis Micro: neutrophil infiltration Consequence: death in acute phase, severe toxaemia and scars, pleural adhesions and abscesses

Answer 166

Definition: highly contagious acute respiratory viral disease Affects: pigs Cause: adaption of type A virus (human influenza), uncomplicated secondary P.multocida, T pyogens Pathogenesis: aerosol, oral route  SIV attaches to and replicates within epithelial cells of upper respiratory tract  spreads throughout nasal, tracheal and bronchial mucosa Macro: bronchopneumonia, severe alveolar and interstitial edema Micro: necrotising bronchitis – bronchiolitis, bronchointerstitial pneumonia

Answer 167

Definition: highly contagious disease Affects: pigs Cause: M. hypopneumoniae, poor management Pathogenesis: Macro: cranioventral loss of cilia, neutrophils and macrophages Micro: fibrous pleural adhesions

Answer 168

Definition: highly contagious Affects: pigs (young) Cause: actinobacillus pleuropneumoniae Pathogenesis: transmission by respiratory route  bacteria attaches to cells  produce pores in cell membranes  damage capillaries and alveolar walls  vascular leakage and thrombosis Macro: fibrinous bronchopneumonia Micro: coagulative necrosis, surrounded by thick cluster of leukocytes, bronchioles filled with oedematous fluid, fibrin, neutrophils and few macrophages

Answer 169

Definition: contagious, retrovirus-induced lung neoplasia Affects: adult, rarely young sheep Cause: retrovirus Pathogenesis: undergoes horizontal transmission Macro: enlarged lungs, heavy, consolidation – cranioventral nodules Micro: neoplastic proliferations – cubic to prismatic cells that form papillary or acinar gland like structures

Answer 170

Definition: Inflammation of visceral or parietal pleurae Types: fibrinous, purulent, haemorrhagic granulomatous and combinations Affects: Cats, pigs, cattle, pig, Cause: haemophilus parasuis, strep, Escherichia coli, Pasteurella, mycoplasma pneumonia or without pulmonary involvement Pathogenesis: bite wounds or penetration of foreign material Macro: pyogranulomas, congestion, pleural effusion Micro: thickening of pleura

Answer 171

Affects: bovine Cause: mycobacterium bovis Pathogenesis: infection of the lungs by inhalation (adult cattle), ingestion of infected milk (young animals) Macro: pearl disease

Answer 172

Definition: accumulation of any fluid in thoracic cavity Hydrothorax: fluid is serous, clear and odourless, caused by increased hydrostatic and decreased oncotic pressure, inflammation and neoplasia Haemothorax: blood in thoracic cavity, caused by rupture of major blood vessel Chylothorax: accumulation of chyle in thoracic cavity caused by rupture of major lymph vessels (thoracic neoplasia, trauma, congenital abnormalities)

Answer 173

Definition: spleen enlargement Cause: blood accumulation, increase in MMS cell number, lymphoid hyperplasia, inflammation and neoplasia Uniform: (bloody) torsion, euthanasia with barbiturates, inflammation and septicaemia, (meaty) phagocytosis, cellular debris Nodular: uneven contraction, hematoma, haemangioma, hemangiosarcoma, infarcts

Answer 174

Affects: cattle and sheep Cause: bacillus anthracis – gram positive bacteria forming endospores Pathogenesis: spores proliferate in intestine  LN  spleen Macro: splenomegaly, disseminated serosal haemorrhages, swollen and oedematous lymph nodes Micro: rod shaped bacteria in blood, congestion, lymphangitis, haemorrhage Necropsy and histopathology aren’t recommended Types: alimentary and pulmonary Consequence: death, haemorrhage

Answer 175

Definition: malignant neoplasia of vascular endothelium Affects: most often in dogs Macro: one or more round masses, reddish to violet colour, fragile coherence Micro: irregular and poorly define vascular spaces constructed from anaplastic endothelial cells

Answer 176

Definition: follicular hyperplasia (B lymphocytes) Macro: addition to the enlargement, capsules’ tensions, the cut surface is protruding Micro: LN – increased due to numerous new lymphoid follicles – secondary lymphoid follicles with pronounced germination centres

Answer 177

Definition: due to the drainage of the area affected by inflammation, the LN becomes infected Macro: enlargement due to fluid accumulation, tissue protrusion on the cut surface, very wet Micro: beginning, infiltration of the neutrophils, followed by more macrophages

Answer 178

``` Pathogenesis: • Skin wound  regional LN • Suppurative lymphadenitis • Abscess • Collision of the abscesses • Caseous necrosis • Fibrous capsule ```

Answer 179

Definition: suppurative inflammation of LN Cause: Strep equi, strep porcinus, Corynebacterium pseudotuberculosis Pathogenesis: LN becomes infected after completing drainage of the area affected by inflammation  C.pseudotuberculosis enters through a break in the skin and spreads to LN Macro: LN enlargement due to fluid accumulation, tissue protrudes on cut surface and is very wet Micro: neutrophil infiltration followed by macrophages, infection with C.pseudotuberculosis there will be eosinophils Consequence: strangles = dysphagia, guttural pouch empyema, c.pseudotuberculosis will progress to caseous inflammation and encapsulated abscesses will form

Answer 180

Definition: tissue and organ damage is caused by the proliferation of macrophages and the immune response of the host Transmission: sand fly Cause: causative agent multiples in macrophages Cutaneous form Macro: ulcers in the location of the insect bite, inflammation Micro: neutrophils lymphocytes and plasma cells Visceral form Macro: generalised Lymphadenomegaly, splenomegaly, hepatomegaly, plasma cell hyperplasia, thrombocytopenia, chronic interstitial nephritis

Answer 181

Cause: histoplasma capsulatum Pathogenesis: organism enters the respiratory system  increase of tracheobronal LN  hematogenic and lymphatic dissemination in organism Macro: generalised Lymphadenomegaly, thickening of the colon wall due to infiltration of macrophages and other inflammatory cells Micro: coalescing granulomas

Answer 182

Definition: various groups of neoplasia that develop from lymphoid tissue outside the bone marrow Classification: location (multicentric, alimentary, mediastinal), immunophenotypic, cell morphology (size, nuclear morphology), histological architecture (diffuse/follicular), biological behaviour (indolent, aggressive) Indolent: slow progression and small, matured and well differentiated lymphocytes. Weak breakdown of the organ structure and a small number of mitosis Aggressive: characterised by rapid progression and large, undifferentiated lymphoblasts. Significant breakdown of the organ structure and large number of mitosis Macro: increased LN, bulging cut surface, grey-white to yellowish, infiltration of spleen, intestinal wall thickness, frequent ulcers Micro: lymphocytes CD34=all

Answer 183

Random: necrosis of individual cells, multifocal necrosis and piecemeal necrosis Zonal: centrilobular, paracentral, midzonal, periportal and bridging Massive

Answer 184

Acute hepatitis: inflammation, hepatocellular necrosis and apoptosis Chronic hepatitis: fibrosis with accumulation of mononuclear cells Non-specific reactive hepatitis: diffuse and nonspecific process; response to some systemic disease Cholangitis: neutrophilic, lymphocytic and destructive Cholangiohepatitis

Answer 185

Regeneration: needs good vascularisation and preserved biliary tree, nodular proliferation Fibrosis: replacement by fibrous tissue, increased amount of fibrous tissue within liver, can be focal, multifocal, diffuse and biliary Biliary hyperplasia: proliferation of bipotential progenitor cells from which biliary ducts and/or periportal hepatocytes can develop

Answer 186

Definition: irreversible change characterised by diffuse fibrosis and conversion of normal liver architecture into structurally abnormal lobules Affects: all Cause: chronic toxicity, chronic cholangitis, chronic congestion, congenital dysfunction, salmonella Pathogenesis: Macro: becomes hard and firm, surface Is uneven and nodular, liver atrophy, yellowish, grey Micro: increased fibrous tissue within and around lobules, infiltration of macrophages and lymphocytes and hepatocytes show degenerative and necrotic changes Consequence: hepatic failure

Answer 187

Definition: excessive lipid within the liver Cause: nutritive causes (def of Vit B12, cobalt), toxic/ anoxic injury, ketosis and fatty liver syndrome of cattle Pathogenesis: Increased dietary intake of fats and carbs  increased esterification  increased fat mobilisation from fatty depots  decreased oxidation due to energy deficiency  decreased synthesis of apoproteins  decreased secretion of lipoproteins from liver Macro: enlarged, yellow liver, mild cases: only pronounced lobular pattern Micro: microvesicular steatosis, macrovesicular steatosis Consequence: significance depends on cause, severity and duration. Hepatocellular necrosis, fatty cysts, fat embolism and liver rupture which can lead to haemoabdomen

Answer 188

Definition: glucose is stored within hepatocytes in the form of glycogen Affects: observed in dogs secondary to excess glucocorticoids Cause: goes with diabetes and glycogen storage diseases Macro: pallor and swelling Micro: hepatocytes are swollen with lacy vacuolated cytoplasm

Answer 189

Definition: accumulation of proteins in beta-pleated sheets Affects: most domestic animals Cause: deposition of insoluble proteins in tissue Types: primary – plasma cell tumours, secondary – long standing inflammation, inherited or familiar Macro: livers enlarged, friable and pale Micro: hepatic amyloid appears as bright eosinophilic amorphous deposits

Answer 190

Affects: dogs Cause: canine adenovirus 1 Pathogenesis: oral infection  tonsilitis  viremia. • Tropism for hepatocytes, endothelial cells and renal epithelium Macro: haemorrhage, enlarged fragile liver, enlarged and hyperaemic tonsils and lymph nodes, gall bladder wall edema Micro: smaller centrilobular necrosis of single cell hepatocellular necrosis, large intranuclear inclusions, endothelial damage with haemorrhage and minimal inflammation

Answer 191

Definition: acute and highly fatal disease Affects: cattle and sheep Cause: clostridium haemolyticum Pathogenesis: bacterial spores are ingested and concentrate within Kupffer cells  fluke migration, hepatic injury  proliferation of vegetative forms of bacteria in anaerobic environment  egzotoxins  hepatocellular necrosis and intravascular haemolysis which is characteristic for the disease  haemoglobinuria Macro: large pale foci of necrosis surrounded by hyperaemic zone, red to yellow fluid within serosal cavities Micro: one or several areas of necrosis with visible bacteria

Answer 192

Affects: most common in cattle and sheep, rare in pigs and horse Cause: clostridium novyi Pathogenesis: spores  lowered concentration of oxygen  bacterial proliferation  exotoxin  coagulation necrosis, haemorrhages, less commonly haemolysis  possibly death Macro: similar as bacillary haemoglobinuria, faster putrefaction Micro: well demarcated areas of necrosis, with gram + rods in necrotic areas

Answer 193

Affects: rodents, young or immunocompromised animals Cause: clostridium piliforme Pathogenesis: causative agent in rodent intestine  peroral infection  via portal vein into liver  lesion Macro: hepatic enlargement, edema, enterocolitis Micro: multifocal necrotising hepatitis, necrotic colitis and stacks of long filamentous bacteria

Answer 194

Affects: horse Cause: unknown – equine parvovirus hepatitis (?) Macro: encephalopathy and icterus, liver is green-brown/dark brown Micro: centrilobular degeneration and hepatocellular necrosis, mild fibrosis and regeneration

Answer 195

Definition: is microscopic changes similar to humans Affects: dog Cause: not clear – leptospirosis, canine adenovirus 1, pharmaceuticals and copper toxicosis Pathogenesis: Macro: smaller liver Micro: portal and periportal mononuclear cellular infiltrate, intrahepatic cholestasis, bridging fibrosis and regenerative nodules

Answer 196

Definition: most malignant tumours are metastatic ones Originating from hepatocytes: benign (hepatocellular adenoma) malignant (hepatocellular carcinoma) Originating from biliary epithelium: benign (Cholangiocellular adenoma), malignant (Cholangiocellular carcinoma) Affects: adenomas mostly in young ruminants Macro: (adenoma)single, unencapsulated, variably size and red or brown masses, spherical, (carcinoma) friable, grey-white or yellow brown tissue Micro: one or very few portal tracts

Answer 197

Affects: most common in ruminants, frequently in domestic animals Pathogenesis: concretions of normally soluble components of bile  form when these components arise due to supersaturation and precipitation of the bile

Answer 198

Definition: hypoplasia of the exocrine pancreas Affects: sporadically in calves; less common sheep, goats and dogs Pathogenesis: • Difficult to differentiate between atrophy – with atrophy there’s lipofuscin within atrophic cells, which isn’t present in hypoplasia Macro: pancreas is small and pale, sometimes there are only visible small wisps of white-cream tissue within the mesentery Micro: acinar tissue is present but scarce, organised in small clusters of cells; poorly differentiated cells without zymogen granules

Answer 199

Affects: German shepherd dogs and rough coated collies Cause: inheritance is complex, likely involving multiple genes and environmental factors, could be atrophy driven by autoimmune disease which precedes loss of normal pancreatic parenchyma Pathogenesis: Macro: pancreas is small, visible loss of parenchyma Micro: islands of normal exocrine pancreatic tissue usually remain but otherwise tissue is markedly depleted

Answer 200

Definition: characterised primarily by necrosis and varying degrees of inflammation of the pancreas Affects: dogs and cats Pathogenesis: 1. Obstruction of the duct (cholelithiasis, parasites, neoplasia) 2. Direct injury to the acinar cells (infectious microbes, toxicants, drugs, trauma, ischemia) 3. Disturbances of enzyme trafficking within the cytoplasm of acinar cells

Answer 201

Acute: most commonly in dogs, less in cats, rare in other animals. Most common in cocker spaniel Macro: edema pancreas, grey-white areas, chalky white foci, abdo cavity contains blood, peritonitis Micro: focally extensive areas of haemorrhage, coagulation necrosis of parenchyma, fibrinous exudate and necrosis of fat in mesentery Cats: 1. Acute pancreatic necrosis 2. Suppurative pancreatitis

Answer 202

Chronic: characterised by fibrosis and parenchymal atrophy, all animal species, consequence of obstruction of the pancreatic ducts, more common in cockers, king Charles, collie and boxer Macro: distorted, shrunken, nodular with fibrous adhesions to adjacent tissues Micro: interlobular and periductular fibrosis and inflammation

Answer 203

Affects: older dogs and cats (can be cattle) Macro: multiple raised, smooth, nodules which are uniformly grey or white on the cut section Micro: nodules consist of unencapsulated aggregates of acinar cells that may lack zymogen granules

Answer 204

Affects: uncommon in domestic species; most common in dogs and cats Macro: solitary/multiple nodules, grey-white to pale yellow, firm to hard consistency Micro: well, differentiated with tubular patterns of undifferentiated carcinomas with solid patterns

Answer 205

Definition: heart failure is the inability of the heart to maintain adequate circulation Acute: refers to sudden, significant loss of cardiac function, without blood pumping through the body, the brain cells die within minutes. Causes: monensin toxicity, myocardial infarct Chronic: heart failure for which there are premonitory signs. Causes: cor pulmonale, ventricular septal defect, fibrosis pericarditis Cause: decreased blood pumping into the aorta or inability to adequately empty the venous reservoirs Pathogenesis: long term overload-induced cardiac hypertrophy is accompanied by myocardial cell death and cardiac fibrosis Macro: cardiac tamponade, pulmonary congestion Micro: myocardial necrosis,

Answer 206

Atrial septal defect: communication between LA and RA, failure of closure of foramen ovale, defect at another site because of failure development of the interatrial septum (boxer and Doberman) Interventricular septal defect: failure of complete development of the interventricular septum  allows the shunting of blood between ventricles (common in English bulldog and springer)

Answer 207

Definition: complicated cardiac anomaly – 4 lesions: 1. Primary defects: ventricular septal defect, pulmonic stenosis, dextroposition of the aorta 2. Secondary defect: hypertrophy of RV myocardium Affects: inherited in keeshond dogs and frequent in bulldogs Pathogenesis: increased pressure in the right side  shunts unoxygenated blood to the underdeveloped left side  systemic hypoxia and polycytemia

Answer 208

Pulmonic stenosis: frequently occurring anomaly in dogs (inherited in beagle), subvalvualr stenosis, valvular stenosis and pressure overload on RV  concentric hypertrophy Aortic and subaortic stenosis: frequently in pigs and dogs, fibrous ring that arises from the endocardium below the aortic valve  may extend to involve cranioventral leaflet of the mitral valve (pigs and dogs) Macro: hypertrophy Micro: A+ S stenosis = altered endocardial tissue has loosely arranged elastic fibres, mucopolysaccharide ground substance and collagen fibres

Answer 209

Definition: accumulation of clear, light yellow, watery, serous fluid Affects: animals with: hypoproteinaemia, heart failure or vascular injury Causes: diseases that have generalised edema, renal failure Macro: pericardial surfaces are smooth and glistening

Answer 210

Definition: accumulation of whole blood in the pericardial sac Causes: blunt force trauma, rupture of hemangiosarcoma, rupture of intrapericardial aorta (horse)

Answer 211

Definition: inflammation of pericardium Fibrinous: frequently – with bacterial septicaemia Macro: both surfaces are covered by yellow fibrin deposits Micro: eosinophilic layer of fibrin with admixed neutrophils Suppurative: mainly in cattle as complication of traumatic reticuloperitonitis, pericardial surfaces Constrictive: chronic inflammatory lesion accompanied by extensive fibrous proliferation and formation of adhesions. Severe lesion constricts the heart with fibrous tissue and can interfere with cardiac filling and thus cardiac output

Answer 212

Affects: dogs – predisposed king Charles, cocker and yorkies Cause: degenerative process Macro: bulbous enlargements on the valve edges, jet lesions without valvular insufficiency Micro: myxomatous degeneration of the valve leaflets

Answer 213

Definition: inflammation of endocardium Affects: often in pigs Cause: arcanobacterium pyogenes, strep, strongylus vulgaris (in horse) Pathogenesis: extra turbulence  damages the valve edges  if bacteria nearby when the valves are damaged, they move in  further thrombosis occurs and bacteria is then protected  multiply Macro: proliferation around the bacteria (vegetative endocarditis), cauliflower like lesions Micro: accumulated layers of fibrin and numerous embedded bacterial colonies Consequence: heart failure, stenosis, embolism and death due to cardiac failure

Answer 214

Definition: chamber of the heart gets too big, or walls of one chamber gets thickened Eccentric: chamber size can be big and cardiac myocytes within the wall are working overtime, it’s associated with volume overloads Concentric: walls of cardiac chambers are really thick and the chamber seems smaller, results from pressure overload Pathogenesis: initiation  stable hyperfunction  deterioration of function associated with degeneration of hypertrophies myocytes

Answer 215

Definition: generalised disease of myocardium Affects: frequent in cats, infrequent in dogs Cause: (primary) idiopathic, (secondary) specific heart muscle diseases Pathogenesis: hypertrophic: sarcomeric defects in cardiomyocytes of which two mutations in cardiac myosin binding protein C have been identified  altered sarcomeric function results in myocytes hypertrophy – LV progressively thickens and lumen narrows  diastolic failure Macro: concentric enlargement Micro: myofiber disarray, fibres instead of lining up in their regular, orderly fashion

Answer 216

Affects: most common in dogs (Doberman, pinschers, dalmatians) also in cats and cattle Cause: inherited as an autosomal recessive mode in Portuguese water dog and dominant in Doberman.. Macro: heart rounded because of biventricular dilation Micro: attenuated wavy fibre, fatty infiltration-degenerative type

Answer 217

Definition: increased stiffness (due to increase myocardial/endocardial fibrosis) of the myocardium that leads to diastolic heart failure Affect: cats, others (?) Pathogenesis: increased stiffness of the myocardium, due to increased fibrosis and infiltration with leukocytes  diastolic heart failure Macro: endocardial thickening

Answer 218

Definition: results of infections spread hematogenously to the myocardium Suppurative: localised of pyogenic bacteria in myocardium (mostly from vegetative valvular endocarditis) Necrotising: toxoplasmosis Haemorrhagic: haemorrhagic and necrotising – often in blackleg Lymphocytic: viral infections: parvoviral myocarditis in puppies; encephalomyocarditis virus infection in pigs Eosinophilic: parasite invasion, idiopathic Cause: Pathogenesis: complete resolution, scattered residual myocardial scars, progressive myocardial damage with cardiac failure Consequence: resolution, scattered residual myocardial scars, progressive myocardial damage with acute/chronic cardiac failure

Answer 219

Definition: neoplasia of vascular endothelium Primary: often arise in the right atrium, specifically the right auricle Secondary: metastasis from spleen Affects: common in German shepherds Macro: red, bloody nodules Consequence: rupture leading to hemopericardium and death from cardiac tamponade

Answer 220

Definition: ductus arteriosus fails to close after birth (smooth muscle in ductus arteriosus fails to contract) Affects: frequent in poodle, collie, Pomeranian, chihuahua, poodles (inherited polygenic trait) Pathogenesis: blood goes from aorta into the lung  too much blood in the lung  lung hypertension  pressure overload on the right heart, which undergoes concentric hypertrophy Consequence: blood goes from aorta to lungs and there’s too much blood in the lungs so pulmonary hypertension and increased preload to LV. Pressure overload on right side so concentric hypertrophy. Blood can start shunting from right to left side so unoxygenated blood going to the body

Answer 221

Definition: intimal fibrosis of large elastic arteries Affects: age- related Cause: probably haemodynamic influences (hypertension) Pathogenesis: Macro: slightly raised, firm, white plaques Micro: accumulation of mucopolysaccharides, later proliferation of smooth muscle cells and fibrosis

Answer 222

Definition: accumulation of deposits of lipid, fibrous tissue and calcium in vessel walls  luminal narrowing Affects: infrequent in animals (pig, rabbit, chicken, dogs with hypothyroidism and diabetes) Pathogenesis: damaged endothelial wall allows lipoproteins to accumulate within intima  oxidised by free radicals generated by macrophages  these are directly toxic to endothelium and smooth muscle cells  cellular debris is ingested by macrophages and form foam cells Macro: arteries – thickened, firm, yellow-white, accumulation of lipids throughout the wall Micro: hyalinisation of CT, proliferation of smooth muscles

Answer 223

Definition: dietary microangiopathy, firm contraction of heart Cause: deficiency of Vit E and/or selenium Pathogenesis: deficiency of Vit E and/or selenium  fibrinoid necrosis and thrombosis of small vessels  microhaemorrhages  discolouration of the epicardial surface, hydropericardium Macro: haemorrhage Micro: endothelial damage, fibrinoid necrosis of small muscular arteries

Answer 224

Definition: highly contagious febrile haemorrhagic disease Affects: pig Cause: pestivirus – RNA virus Pathogenesis: inhalation of virus from direct contact with infected pigs or by ingestion of uncooked infected pork  penetrates oral mucosa  viral replication (tonsils)  viremia  damage of endothelial, epithelial and cells of the immune system Macro: widespread petechial haemorrhages, infarction of spleen “button ulcers” of colonic mucosa Micro: hydropic degeneration of endothelial cells, fibrinoid necrosis of blood vessels Consequence: death

Answer 225

Definition: blood vessels of the placentas from two different foetuses fuse and exchange blood between foetuses Freemartin: female of a set of male and female twins Affects: chimeras most common in DSD Macro: clitoris is enlarged, small ovaries, hypoplastic vagina Micro: Sertoli cells and seminiferous cordlike structure in ovaries

Answer 226

Affects: in cattle Cause: bovine herpesvirus 1 Pathogenesis: AI, mating and maybe nose to vulva contact Macro: focal ulceration of mucosa of the vestibule, multiple white regions Micro: eosinophilic intranuclear inclusions, ballooning degeneration and apoptosis and desquamation

Answer 227

Definition: accumulation of pus within the uterine lumen Cause: consequence of endometritis or metritis, E.coli (viscous brown exudate), strep (creamy yellow) Macro: necrotic, ulcerated haemorrhagic areas in endometrium Micro: cystic endometrial hyperplasia Consequence: widespread extramedullary haematopoiesis and immune complex glomerulopathy

Answer 228

Definition: endometrium is found on serosal surfaces, around the ovary

Answer 229

Definition: inflammation of the uterus Cause: bacterial infections (klebsiella), mechanical, thermal and chemical factors, strep, staph Pathogenesis: • (acute) Catarrhalic endometritis, septic metritis, necro bacillary metritis, contagious equine metritis • (chronic) suppurative, nonsuppurative and granulomatous = pyometra

Answer 230

Definition: infectious bacterial disease Cause: Br ovis, abortus, canis Pathogenesis: ingestion/inhalation --> multiply in reg LN --> through intestinal epi and Peters patches --> lymphatics Macro: foetus edema, bronchopneumonia, pleuritis Micro: inflammation, edema and mononuclear and few neutrophils

Answer 231

Follicular cysts, lutein cysts, cystic corpus luteum Affects: all domestic animals Cause: hormonal and nutritional disorders and toxins

Answer 232

Definition: (not ruptured graafian follicle) Affects: cows, pigs Cause: E.coli Pathogenesis: 1. Abnormality in the hypothalamus – pituitary-ovary axis 2. Associated with infection (E.coli) 3. Increased prostaglandin due to bacterial endotoxin 4. Increased cortisol 5. LH suppression 6. Cysts formed  increased ACTH or cortisol 7. Inhibition of release of GnRH and decreased expression of LH receptor in ovary  cysts Macro: cyst fluid – rich in oestrogen

Answer 233

Definition: formed from corpus luteum – after ovulation and the extension of the follicular areas Cause: hormonal, eating disorders and toxins Pathogenesis: not clarified

Answer 234

Affects: cows, mares and bitches (mostly benign), cats and bitches (malignant) Pathogenesis: Macro: unilateral, smooth surface, round, solid, cystic Micro: cells similar to granulosa cells, round or cylindrical, stroma is scant to abundant

Answer 235

Definition: inflammation of parenchyma (mastitis) and excretors channels (galactophoritis) Classification: severe, suppurative, subclinical and granulomatous Cause: bacteria and mycoplasma Infection: galactogenic, hematogenic and lymphatic Predisposing factors: high producing, excessive high vacuum, presence of lesions, contamination, poor hygiene and certain flies

Answer 236

Affects: cow Cause: G+ (staph, strep) Pathogenesis: Macro: edema of the mamma and surrounding areas, milk is watery, contains fibrin

Answer 237

Definition: without clinically apparent necrosis of tissue or with necrosis Affects: Cause: Gram – and + bacteria Pathogenesis: Macro: edema, fibrin exudation, neutrophilic infiltration Micro: necrosis and sequestration of glandular tissue

Answer 238

Definition: pus forming Affects: dry cows Cause: trueperella pyogenes, mcyoplasma bovis Pathogenesis: Macro: lesions are centred on lactiferous ducts and sinuses Micro: neutrophils

Answer 239

Cause: microbes, candida Pathogenesis: Macro: glands, hot, swollen, multiple abscesses, small white particles in exudate Micro: granulomas and pyogranulomas surrounded by fibrous tissue – gland being replaced by framework of fibrous tissue surrounding pockets of inflammatory cells and central necrotic debris

Answer 240

Definition: most important in bovine Affects: bovine Cause: strep, inadequate mammary hygiene and efficient antibacterial drugs Pathogenesis: bacteria persists in lactiferous sinus and multiples Macro: strands/clumps of debris or pus are present in the milk, parenchymal edema, alveoli with retained secretion Micro: interstitial edema, neutrophils infiltration, alveolar epithelium, macrophages and inflammatory cell

Answer 241

Definition: most severe form of this is gangrenous form Affects: Cause: staph Pathogenesis: Macro: blue-black colour, fluid exudation Micro: severe interstitial edema

Answer 242

Definition: Affects: Cause: gram – bacteria (klebsiella, Escherichia coli) Pathogenesis: endotoxin and subsequent cytokine release Macro: fluid in lactiferous sinus Micro: edema of the interlobular septa, fibrin thrombi in lymph vessels, epithelium of ducts and alveoli necrotic

Answer 243

Definition: Affects: cows Cause: mycoplasma bovis Pathogenesis: hematogenous spread and contamination of the papilla Macro: affected quarters are enlarged, firm, light brown, nodular parenchyma Micro: vacuolisation, degeneration of alveolar epithelia, fibrosis

Answer 244

Definition: disruption of intercellular junctions between keratinocytes Cause: immune mediated injury (pemphigus), exfoliative toxins from staph Pathogenesis: damage of transmembrane glycoproteins  splitting of extracellular core of desmosomes  desmosomes plaque dissolve and intermediate filaments retract Micro: varies depending on location, vesicles/pustules and free-floating keratinocytes

Answer 245

Vesicles: fluid-filled cavities within or beneath the epidermis less than 1cm Bullae: vesicle greater than 1cm

Answer 246

Definition: incomplete development of skin epithelium  ulceration Affects: cattle, dogs, pigs and sheep Cause: secondary bacterial infection  bacteriemia Consequence: tissue is easily traumatised leading to secondary bacterial infections and bacteraemia, death from infection of dehydration and electrolyte imbalance Macro: sharply demarcates areas devoid of the epidermis and adnexa or mucosa Micro: no epidermis

Answer 247

Definition: alopecia – absence of hair from skin where hair is usually present, hypotrichosis – less than the normal amount of hair Affects: most domestic animals Cause: hereditary conditions caused by spontaneous genetic mutations

Answer 248

Definition: activation of photodynamic substances in skin with UVA Type 1: Primary, ingestion of photodynamic substances in food (hypericin) or medicines, in the intestine is transformed into a photoreactive metabolite Type 2: abnormal metabolism of porphyrin – inherited disease (cattle and cat) Type 3: hepatogenous photosensitisation – occurs secondary to primary liver damage Pathogenesis: activation of photodynamic substances in skin with UVA  ROS formation  mast cell degranulation  inflammatory mediators  damage of cell membranes, nucleic acids, proteins and organelles  erythema, edema, exudation and necrosis Macro: lesions in areas with unpigmented skin exposed sunlight, peracute development  erythema, edema, vesicle and necrosis Micro: coagulative necrosis of the epidermis, fibrinoid vascular degeneration and secondary bacterial infections

Answer 249

Cause: persistent licking or chewing Pathogenesis: Macro: erythematous, haired or hairless, ovoid, eroded plaque Micro: hyperkeratosis, acanthosis, erosions, ulcers; dermis thickened by fibrosis and capillaries

Answer 250

Definition: contagious pustular dermatitis Affects: sheep and goat Cause: parapoxvirus Pathogenesis: abrasions  infections  lesions characteristic for poxvirus Macro: ulcers

Answer 251

Affects: cows, bishops Cause: capripoxvirus Pathogenesis: infections of the skin  viremia  systemic infection  endothelial damage  vasculitis  eruption of numerous, well-restricted nodules on the skin, edema, generalised lymphadenopathy Micro: vasculitis, lymphangitis, thrombosis, changes In epidermis

Answer 252

Pathogenesis: infection  epithelial cells – replication  lysis of nuclei  viral particles enter the cytoplasm  degeneration of cytoplasmic organelles, cytoplasmic lipid accumulation and protein precipitation Macro: vesicles that rupture  ulcers  crusts Micro: balonising and reticular degeneration – acantholysis, occasionally syncytial cells, intranuclear inclusions

Answer 253

Definition: species and site specific pathogens Affects: Cause: Pathogenesis: infects squamous epithelium, fibroblasts  cause benign, less commonly malignant tumours Virus in the cell – 3 possible outcomes: 1. Virus remains in circular DNA episome  replicate but latent 2. As basal cells mature  virus convert to productive infection with typical morphological changes 3. Virus can become integrated into the genome of host cells  malignant transformation  neoplasia Macro: warts, ulcerated fibrous growths Micro: epithelial hyperplasia (thickened)

Answer 254

Definition: locally aggressive, nonmetastatic fibroblastic tumour, frequently in areas subjected to trauma Affects: Equine Cause: BPV 1 and 2 Pathogenesis: Macro: Occult (flat grey hairless, circular), verrucous (grey, scabby, solid), nodular (multiple, discrete), fibroblastic (fleshy mass), mixed, malevolent (rare + aggressive) Micro: epithelial hyperplasia

Answer 255

Affects: horse, cattle and sheep Cause: dermatophilus congolensis Pathogenesis: repeated cycles of bacterial growth, inflammation and epithelial regeneration  formation of stratified pustular crusts Macro: crusty lesions

Answer 256

Definition: exudative epidermitis of pigs Cause: staphylococcus hyicus – toxin Pathogenesis: bacteria release exfoliatin toxin which erodes straum corneum Macro: brownish malodorous exudate, hardens, cracks and becomes scaly Micro: sub corneal pustular dermatitis, superficial suppurative folliculitis, thick crusts of keratin, microabscesses and cocci Consequence: if acute, it’s fatal in neonatal piglets

Answer 257

Definition: atopic dermatitis (atrophy, allergic inhalant dermatitis) Cause: genetically predisposed inflammatory and pruritic allergic skin disease

Answer 258

Definition: benign tumour of stratified squamous or transitional epithelium • Well differentiated tumour, exophytic growth, papillae or plaques, hyperplasia of epidermis and hyperkeratosis, gentle fibrovascular stroma

Answer 259

Definition: most common malignant epithelial tumour • Poorly demarcated, locally invasive, rare metastasis Affects: cats Cause: UV rays

Answer 260

Definition: malignant, more common (oral mucosa) Affects: Cause: Pathogenesis: high pleomorphism and atypia, degree of pigmentation Macro: spindle, round, epithelioid, vesicular cells, higher mitotic count Micro:

Answer 261

Definition: malignant neoplasm of connective tissue or mucosal mast cell origin Affects: dogs, cats, pig and cattle, most common in dogs, mainly in the back of body and scrotum Grading: Macro: can look like inflammation due to degranulation and release of mediators Micro: eosinophils, flame figures and with toluidine blue stain, mast cells are purple

Answer 262

Definition: benign tumour Affects: young dogs Macro: oval, solitary, fast growing, rising above the skin, alopecia Micro: solid infiltrative growth, pleomorphic histiocytes, frequent mitosis

Answer 263

Definition: disorder of cornification, characterised by an increase in the thickness of stratum corneum Cause: non-specific response to trauma, inflammation or sun exposure, primary seborrhoea of cocker spaniels and vitamin A deficiency Orthokeratosis: keratinocytes undergo complete cornification and become anuclear, there’s also hypergranulosis Parakeratosis: keratinocytes undergo partial/incomplete cornification and retain their nucleus. There’s also hypogranulosis Types: basket weave, compacted or laminated Diffuse parakeratosis occurs in hepatocutaneous syndrome

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