Exam 1 Path II Flashcards

Question

What is the name of this? What are 3 etiolgy? Pathogenesis?

Answer 1

**Erosive-Ulcerative Stomatitides** ## Footnote (1) dogs and cats with renal disease (2) BVD in cattle (subtle lesions) (3) MCF in cows (more severe) NO vesicle formation. Due to presence of vasculitis that leads to damage of the surface epithelium and exposure of the lamina propria.

Answer 2

**Tiger Heart** acute myocardial degeneration and necrosis (pale stripes) that causes high mortality in young animals Seen in Foot and Mouth Disease

Answer 3

**Bovine Papular stomatitis** Etiology: **Parapoxvirus** Papules on the nares, muzzle, oral cavity. Usually present in immunosuppressed individuals. Appear as “**Coin-Shaped papules and Ulcers**”, the virus is closely related to pseudocowpox virus that causes “milker’s nodule in humans (hands)”. See proliferation/**raised** epithelium due to hyperplasia of keratinocytes. See **ballooning degeneratio**n and **eosinophilic intracytoplasmic inclusion bodies**

Answer 4

**Oral Necrobacillosis** Fusobacterium necrophorum (filamentous bacteria part of normal flora) in calf, sheep and pigs “Calf Diptera” – ulcerative/necrotizing inflammation in oral cavities, pharynx and laryngitis Complication- problems eating and aspiration pneumonia due to necrotic exudates

Answer 5

Etiology believed to be immune mediated hypersensitivity due to response to corticosteroid therapy

Answer 6

Tumor of the **periodontal ligament**– type stroma Fibromatous and ossifying epulis are **benign**.= GOOD PROGNOSIS Treat surgically Histological- proliferation of periodontal epithelium embedded into fibroblast stroma

Answer 7

(previously known as acanthomatous epulis) **locally aggressiv**e and often **recur** after excision – **poor prognosis** behaves like squamous cell carcinoma (except this tumor **does not metastasize**)

Answer 8

**Canine oral papillomatosis** Papilomavirus-induced papilliform or cauliflower-type lesions (“warts”) in the lips and oral mucosa It is transmissible and usually affects animals younger than 1 year-old. Lesions regress spontaneously and immunity is long-lasting. Verrucous lesion composed of thick keratinized stratified squamous epithelium covering a pedunculate connective tissue core.

Answer 9

Most common in dogs. Poor prognosis. Around 90% of oral melanomas in dogs are malignant – see pulmonary metastases Predisposing factors: Smaller breed and oral pigmentation May lose pigmentation =**amelanotic**

Answer 10

Tonsils and tongue

Answer 11

_Caused by_ persistant right aortic arch (PRAA) primarily in dogs (German Shepards are predisposed) _Occurs when_ the right aortic arch develops instead of the left. This leads to the ligamentum arteriosum forming a vascular ring around the esophagus, causing compression. The dilitation will be _located_ directly cranial to the heart. _Side effects_: weight loss, accumulation of feed, regurgitation, **aspiration pneumonia**

Answer 12

_Causes_: (1**) Idiopathic** (2) **Maniestation of myasthenia gravis**- immune mediated destruction of ACh receptors causes relaxation of the esophagus (3) **Polymiositis** _Location_: immediatly cranial to the stomach

Answer 13

_Cause:_ Due to obstruction (potatoes, apples, corn cobs) _Location_: where impaired dilatation due to hard structures (1) Dorsal to the larynx (2) Thoracic Inlet _Consequence_: (1) Impaired eating and drinking (2) Compression necrosis

Answer 14

Reflux of gastric acid causes chemical burns on the distal/aboral esophagus. Most common cause of esophageal erosion and ulcers. Common in **pigs** due to the high incidence of **gastric ulcers** that damges the esophageal portion of the stomachc and leads to an increase in reflux.

Answer 15

**Erosive-ulcerative esophagitis** due to **BVD** (pestivirus) See multiple variable sized and shaped ulcers. Lesion are also seen in the oral cavity and sometime the intestines.

Answer 16

Spirocerca enters the stomach mucosa --\> travel through the aorta to the esophagus Causes **caseous granulomatous esophagitis** that usually has communication with the lumen so that eggs can be released. May lead to **malignant neoplastic transformation** causing the formation of mainly **osteosarcomas and fibrosarcomas.** Common in dogs in the caribbean

Answer 17

Ruminal Tympany or Bloat= Over distention of the rumena dn reticulum by gases produced during fermentation * **Primary** - associated with new diets of highly fermentable products that cause the formation of stable foam * **Secondary**- due to physical obstruction of the esophagus that prevents eructation of gas * Obstruction can be due to vagus indigestion, esophageal papillomas, and lymphosarcomas that cause lymphanditis

Answer 18

* Distended **left** abdomen and paralumbar fossa. * (pregnancy causes right side distention) * **Respiratory signs due** to increase pressure on the thoracic cavity * **Cranial congestion** due to pressure on blood vessels * **Frothy ruminal content** (primary bloat) * Decreased/**Acidic ruminal pH** (primary bloar) * **Bloat Line** at the thoracic inlet

Answer 19

**Traumatic reticulitis/ "hardwear disease"** Caused by ingestion of sharp objects (bovine lips prevent them from being very discriminat when eating) that then enter the reticulum. During rumination, the contractions of the reticulum causes perforation of the object into the reticulum wall. If severe, the forign object may also puncture the diaphram, pericardium (pericarditis & CHF), heart or lungs (pneumonia). Animals appear in pain, be reluctant to more or stant on unlevel group to prevent any further pressure on the foreign object. Magnets are sometimes fed to cattle to prevent reticulitis. To check for traumatic reticulitits during necropsy you should feel between the diaphram and reticulum for any forign bodies or fibrin adhesions.

Answer 20

**Chemical Ruminitis** Common in feedloack cattle due to high carbohydrate diet that leads to an increase in fermentation in the rumen --\> acidic pH--\> damage and necrosis of the mucosa See sloughing of the mucosa that exposes VERY RED, inflammatory submucosa with areas of necrosis, degeneration and pustules (compare to post-mortum ruminal sloughing) Can treat by surgically removing ruminal contents and replacing them with a healthy ruminal contents from slaughtered animals. If survive you will have development of Stellate ulcers and/or portal showering of bacteria

Answer 21

**Stellate ulcers** Ruminal scars of animals that survive grain overload

Answer 22

* Sudden death * **Portal showeing of bacteria** - mucosal damage causes ruminal flora to enter the sytemic circulation via the portal vein. See **hepatic abcesses and necrosis** * Fibrinonecrotising ruminitis * **Secondary mycotic ruminitis** (picture) * **Stellate ulcers**

Answer 23

**GDV- Gastric Dilatation volvulus** _Occurs in_ **dogs and sows** after they eat/drink large amounts and then excersise _K9 Clinical signs:_ progressive abdominal distention, non-productive retching, hypersalivation and restlessness. _Stomach looks_ dilated, red, swollen and friable. _Spleen_ may be displace to the right side due to the gastrosplenic ligament. **Surgical emergency!** if wait to long you can have venous infarction --\> necrosis--\> intraluminal hemorrhage.

Answer 24

Occurs most often in **post-parturient dairy cows** and calves _Left-sided_ is **most common**: generally non-fatal due to only **partial obstruction** of abomasal flow _Right-sided_: Represent **~15%** of the abomasal displacement. 20% of these **result in abomasal volvulus**. _Clinical Signs_: abdominal pain, elevated heart rate, **anorexia**, dehydration, depressed peristalsis with lack of feces and abomasal tympany (**high-pitch ping** elicited by percussion).

Answer 25

**Gastric Impaction/Rupture** _Occurs in horses due_: (1) **intestinal obstruction (ilius)** --\> adynamic (paralytic) or mechincal ileus that inhibits bowel motility and gastric emptying. \*\* MOST COMMON\*\* (2) **high grain diet** with large amounts of water-- due to exspansion (3) **Chronic diaphramatic hernia** - may see gastric contents within the thoracic cavity (4) Persimmon ingestion _Prevention_ Horses are unable to vomit, so if a horse is colicing you should pass a nasogastric tube to releive the pressure. _How to tell it is ante-mortem_: Hemorrage!

Answer 26

Gastric ulcers in pigs typically occur in the **esophageal portion** of the stomach (was covered by stratified squamous epithelium). _Clinical signs:_ due to chronic internal bleeding there is **melena & anemia** (white pigs will look very pale). In severe cases, the ulcer may perferate --\> peritonitis --\> death _Cause_: Finely ground feeds stimulate excessive Cl production in the stomach. High wheat compenents in feed also plays a role.

Answer 27

Etiology: stress, immunosuppression, highly fermentable diets, NSAIDs, ideopathic In young horses: near margo plicatus & ideopathic

Answer 28

Often occurs after using NSAIDs in colic patients. Colic patients are typically dehydrated, thus even normal doses of NSAIDs can cause issues. Occurs due to NSAIDs reducing prostoglandins that become PGE2 & PCl1- which have a protective role. May also see intestinal ulcerations.

Answer 29

Mast cell tumors cause the **release of histamine** into the blood. Histamine binds to receptors on parietal cells and causes them to i**ncrease HCl secretion** If severe, dogs may develop **perforated gastroduodenal ulcer** that can lead to **fatal peritonitis.**

Answer 30

**Gastric Inflammation** of a **Pig** in the **fundus** region of the stomach Occurs **secodnary to endotoxemia or bacterial sepsis** (**salmonellosis** is most common, e.coli, glassers disease) that causes **gastric venous infarction**. Gastric mucosa will be dark red and may have fibrin exudate and an increase of mucous production. This occasionally is seen in **ruminants and horses**

Answer 31

In the fundus of the stomach Secondary to bacterial sepsis - ie salmonellosis

Answer 32

**Uremic gastritis** in **small animal** patient with **renal failure** Gritty consistancy and whitish color is due to **diffuse mineralization.** Diffuse mineralization can be seen as diffuse black dots on histology with a **Von-Kossa staining**. Uremia lead to vascular lesions that cause damage to the mucosa of the stomach and intestines. Clinical signs of uremic gastritis include chronic vomitting and diarrhea. May also see **ulcerative glossitis** in renal failure patients

Answer 33

***Clostridium septicum*** causes Bacterial gastritis/abomasitis - Braxy (Bradshot) **Clostridium septicum** is a gas producing bacteria, thus it will present as fiable, edematous, hemorragic necrotising and **emphysematous** gastritis Occurs after i**ngestion of frozen food** that contain the bacteria and cause mucosal damage.

Answer 34

**_Mycotic gastritis/abomasitis_** caused by **angio-invasive fungi** (Aspergillus, Absidia, Rhizopus, Mucor spp. etc.) that have a predilection to blood vessels and cause **_mycotic vasculitis/perivasculitis_ and thrombosis** that result in **round focal areas of ischemia.** Multifocal lesions are necrohemorragic and typically covered with a **fribinonecrotic exudate mixed with fungal hyphae** Common sequel of **long-term antibiotic therapy**, immunosuppresion, debilitating conditions (sepsis) and grain overload. Can confirm fungal hyphae around blood vessels via GMS stain.

Answer 35

Parasitic gastritis due to ***Gasterophilus nasalis*** and ***intestinalis = Bot fly larvae*** ***Gasterophilus nasalis*** is located close to the intestines ***G. intestinalis*** is close to the esophageal portion of the stomach **NO CLINICAL SIGNIFIGANCE**- even in severe infestation

Answer 36

**Proliferative (hyperplastic) abomasitis** due to ***Ostertagia*** **spp.** “Moroccan leather” appearance

Answer 37

**Draschia megastoma** (nematode) brood pouch causing a **Granulomatous gastritis.** Will be able to find nematode within...

Answer 38

Trichostongylid nematode ***Haemonchus contortus***"Barber pole worm" **Severe parasitic abomasitis** results in chronic blood loss --\> anemia & hypoproteinemia & melena

Answer 39

Gastric **squamous cell carcinoma** Arises in the **esophageal portion** of the stomach. It may looked depressed or proliferative, may be surrounded by digested blood. It is locally aggressive and will penetrate and invade all muscle layers of the stomach wall and then cause **peritoneal carcinomatosis** via transcoelomic transplantation. _Clinical signs_: weight loss and internal bleeding (anemia & melena) One of the most common tumors in horses in general.

Answer 40

**Gastric Lymphosarcoma** Occurs in **ANY species!** Have to differentiate from **Drashia**. _Lymphosarcomas are_ located everywhere and will have a **solid** appearance and no presence of parasites. Ulcers seen in esophageal portion of the stomach of the picture is probably due to the stress of the animal having a tumor.

Answer 41

**Bovine Leukemoa virus = Enzootic Leukosis** Enlarged lymph nodes and multicentric lymphosarcoma. **Abomasum folds will be thickened and nodula**r. On a cut surface there is presence of a **solid pale-tan tissue.** Mass in the submucosal causes compression of blood vessels --\> ischemia --\> necrosis. May have ulceration and see melena.

Answer 42

Atresia coli is the most common segmental anomaly of the intestines in domestic animals. Range from **stenosis** (incomplete occlusion of the intestinal lumen) to **atresia** (complete occlusion/ obliteration of the intestinal lumen). Due to ischemia of gut during fetal development. Autosomal recessive trait in **hosteins calves** Will be unable to deficate and have abdominal distension due to megacolon.

Answer 43

**Atresia ani = imperforate anus** Females may be able to survive this condition longer if they form a concomitant recto-vaginal fistula. Will have distended megacolon --\> abdominal distenstion

Answer 44

American Paint Horses

Answer 45

**Lethal White Syndrome / Congenital Colonic Aganglionosis** Autosomal recessive genetic disorder in which completely/mostly white horses will lack of myenteric and submucosal parasympathetic ganglia in the wall of the ileum, cecum and colon. Leading to intestinal immotility and colic shortly after birth. Grossly on necropsy the large colon and cecum will be reduced in size and you will not see any parasympatheitc ganglion. Foal is unable to eliminate the "first feces"/Meconium that contains sloughed cells and other contents --\> colic.

Answer 46

**Entrolith** Composed of concentric lamellae of magnesium, ammonium phosphate (struvite) deposit around a “nucleus” foreign body such as a nail, wire etc. Vary in size, some may weight up to 10 kg.

Answer 47

Trichobezoar= **Hair ball**!! Found in cats, dogs and cattle. Can cause obstruction. Not as heavy as enteroliths.

Answer 48

Phytobezoars= **plant material** impregnated with some **phosphate salts** May be found in the **colon of horses.** If mixed with hair it is referred to as **phytotrichobezoars**

Answer 49

Pigs and Foals May cause obstruction

Answer 50

**Rectal Stricture** in pig due to **salmonellosis** (*S. typhimurium*) Salmonella causes vasculitis of the cranial hemorrhoidal artery --\> ischemia --\> helaing by fibrosis --\> stricture and stenosis. Pig will also have abdominal pain and distention due to megacolon.

Answer 51

***Salmonella typhimurium***

Answer 52

**_Internal hernia:_** Displacement of intestine through a normal or abnormal foramina **within the abdominal cavity (rare).** Examples: incarceration (entrapment) of loops of the intestine within the slit-like epiploic foramen, or a rent (tear) in the omentum or mesentery. **_External hernia:_** Displacement of loops of intestine, omentum and occasionally other viscera (hernial contents) **outside the abdominal cavity**. Displaced contents are inside of a pouch (hernial sac, formed by the peritoneum and the skin) which protrudes through the hernial ring - an opening in the abdominal wall which could be acquired or natural (e.g.: vaginal ring of the inguinal canal).

Answer 53

Eventration= When displaced abdominal contents are **not covered by parietal peritoneum or skin the lesion.**

Answer 54

**Diaphramatic Hernia** Due to trauma or congenital (loose diaphramatic hiatus) Will se respiratory sigsn and hear abdominal sounds within the thorax,

Answer 55

Incarceration= **fixation** of loop of intestine within the hernia. Can lead to venous infarction, sepsis and death

Answer 56

Torsion! Wrapping of the intestines around itself. Sequel= venous infarction --\> **congestion** --\> necrosis --\> endotoxemia --\> septic shock

Answer 57

torsion of a piece of intestines along its mesenteric axis Segment will be dark red due to congestion, as well as edematous and friable.

Answer 58

**Pedunculated lipoma** Benign tumor of adipose tissue that arises from the mesentery. Tumors may have a stalk/peducle attached to them that can twist around section of intestions. Common in old horses. If necrosis of the center of a large lipoma there will be dystrophic mineralization and the lipomas will become heavy and more likely to twist around intestines.

Answer 59

**Intussescipiens**- portion "eating" the other section of intestine. Outside **Intussesceptum**- smaller portion within another section of the bowel. Inside.

Answer 60

Enteritis --\> **increased peristaltic activity** Parasite infestation Ideopathic!

Answer 61

diarrhoea which leads to dehydration, acidosis, malabsorption, hypoproteinemia, electrolyte imbalance. Can have portal showering of bacteria & fatal endotoxic shock

Answer 62

**Payer patch necrosis** & areas of subtle **ulceration** in the oral cavity, forestomach and intestines. May be mild or subclinical. **Mucosal disease** (most severe form) occurs commonly in persistantly infected (immunotolerant) animals that develop/obtain a cytopathic strain of the virus. Affected animals are usually 6-12 months of age.

Answer 63

MCF infects a variety of ruminant (bison, cervids) and sheep in the USA. Low morbitity, high mortality Produces fibrino-necrotizing vasculitis with prominant perivascular infiltrates on many organs and tissues (ex. kidney) Also damages lymph node tissies. Vasculitis will lead to erosion and ulceration in the oral cavity, Gi tract and on the coronary bands.

Answer 64

Transmissible gastro-enteritis (TGE) in pigs and common cause of neonatal diarrha in calves (w/ rotovirus and cryptosporidium). Causes severe villous atrophy/blunting of the tios and sides of the villi Gross: intestinal wall will be very thin (due to villous atropy) and you will see fluid and gas as the intestinal contents.

Answer 65

Causes diarrhea in young animals (all species) Causes damage to surface/tip enterocyes resulting in variable degreems of strophy Subclinical infections are common in piglets.

Answer 66

Caused by **CPV-2** and Feline Panleucopenia virus. Targets fast resplicating cells in the **intestinal crypts cells** and bone marrow (in Feline form) Serosal surfaces will look granular and red. Causes Segmental fibrino-hemorrhagic enteritis, necrosis of peyers patches, and issues associated with bone marrow suppresion (in cats) May see unique regenerative changes in the remaining crypt cells or intranuclear inclusions. FeLV in older cats will produce similar enteritis lesions.

Answer 67

**FIP** -very important cat disease _Two forms_: (can have both) (1) **Wet form**: peritoneal and thoracic perfusion due to vasculitis (2) **Dry form**- solid puogranulomatous lesion due to vasculutis Will commonly see gray plaques on the surface of the intestines, liver and spleen. Also in alignment with the blood vessels of the cortex of the kidney

Answer 68

FIP maybe lymphosarcoma

Answer 69

**Enterotoxigenic colibacillosis**= Secretory diarrhea (enterotoxininduced) in Neonatal pigs, calves and lambs **Septicemic colibacillosis**=Failure of passive transfer of maternal antibodies in Neonatal calves, pigs, foals. Enteritis is not common –sudden death or subacute & chronic disease (meningitis, polyarthritis etc) **Post- weaning colibacillosis**= Similar to enterotoxigenic colibacillosis with secretory diarrhea & mild or no lesions **Weaner pigs Attaching & Effacing** - attached to surface enterocytes and cause villus atrophy. Some may not produce toxins. In Pigs, dogs –less common in other animals.

Answer 70

**Edema disease** (enterotoxemic colibacillosis) Caused by strains of E. coli that produce the edema toxin that cause endothelial cell injury in arterioles resulting in fluid loss and edema. It is most common in pigs a few weeks after weaning. Will see diffuse edema, specifically a swollen face, periorbital edema and edema of the mesentery of the spiral colon. Affected animals may exhibit focal bilaterally symmetric encephalomalacia (``Cerebrospinal angiopathy of swine``) after the acute phase due to blood vessel damage that leads to cerebral edema and degenerative changes.

Answer 71

*Clostridium perfringens* Type D See severe hemorrhagic lesions in the intestines

Answer 72

young, best nourished animals in the group

Answer 73

Angiotoxin/Epsilon toxin toxin has predilection for blood vessels within the brain (Will also see severe hemorrhagic enteritis)

Answer 74

**Type A** (& C) Lesion are similar to Type D= necrohemorragic enteritis Will see layer of gram negative bacilli on surface layer of intestines in histology.

Answer 75

***Clostridium piliforme*** Main target is liver, but lesion also on intestines (port of entry) and heart

Answer 76

***Clostridium perfringens* typa A & *_Clostridium difficile_*** Fibrinonecrotizing Typhlocholitis in horses Result of dysbacteriosis ( associated with antibiotic therapy or dietary change) leadin to proliferation of toxigenic clostridia

Answer 77

ALL species are pathogenic Disease range from enterocolitis to septicemis Causes **ulcerative & fibrinonecrotizing enterocolitis** Intestinal contents will be malodorous and contain **mucus, fibrin** and occasionally **blood** (feces: “septic tank odor”). Mucosa will be thickened (edema), friable, with areas of hemorrage and necrosis with fibrin and mucous on surface Stress factors play a role Zoonotic and nosocomial (common in horse hospitals) _Complications of disease_: **embolic mycotic pneumonia** (multifocal necrohemorragic with red margins due to secondary angioinvasive fungi) **Rectal strictures** --\> megacolon

Answer 78

Fibrino-necrotizing entero-colitis DDx: Salmonellosis or Colitis X

Answer 79

**Embolic mycotic pneumonia** **Sequel of Salmonellosis** Due to opportunistic angiovasive fungi from intestinal contents

Answer 80

**Button Ulcers** DDx: **Chronic Salmonellosis -or- Hog Cholera (CSF)** Can lead to rectal stictures --\> megacolon

Answer 81

***Lawsonia intracellularis*** **Porcine Proliferative Enteropathy (PPE)** Common in the enterocytes of the **ilium**\*\* and late jejunum of weaner and young pigs. Intestines will have "**garden hose appearance**" due to the mark thickening May become **proliferative hemorrhagic enteropathy** in older animals= intestinal contents will be blood. High mortality, low morbidity. Use **silver stain** to see bacteria.

Answer 82

Swine Dysentry (Spirochetal colitis) Caused by ***Brachyspira hyodysenteriae*** Affect **pigs 8-24 wks** (low incidence in USA) Large bowel diarrhea with mucus and blood in feces Will had edema/thickening of the wall, ulceration, hemorrage, fibrin, **mucous (bacteria induces goblet cell hyperplasia) within the large intestines.**

Answer 83

* Causes an enterocolitis in young horses * Virulent factors allow the bacteria to **survive within the cytoplasm of macrophages** and cause chronic disease * Typically R. Equi is **associated with suppurative pyogranulomatous pneumonia in foals.** * The **enteric lesions are ulcerative and pyogranulomatous** and are associated with **prominent regional lymphadenitis.** * Also, causes **osteomyelitis** in horses

Answer 84

Pyogranulomatous lymphadenitis, R. equi

Answer 85

Rhodoccocus equi pyogranulomatous pneumonia

Answer 86

**Johne's Disease** (Mycobacterium avium paratuberculosis) Chronic disease of rumunants Characterized by D, emationation and hypoproteinemia. Usually occurs in animal older than 19 months Low morbidity Lesions are most likely in the ileocecal area= cerebriform appearance due to granulomatous inflammation (M0 are the main component). Also found in the lieum, cecuma and proximal colon. Acid fast stain will confirm diagnosis _Sheep_ typcally have subtle lessions but will exhibit prominant/thickened lymphatic vessels due to pyogranulomatous lymphangitis

Answer 87

Johnes Diseas Sheep typcally have subtle intestinal lessions but will exhibit prominant/thickened lymphatic vessels due to pyogranulomatous lymphangitis

Answer 88

**Granulomatous Colitis** due to **special strain of** **E. coli** Genetic component See multifocal ulcerative lesions of the colon that may have raised borders due to the pyogranulomatous reaction. Will see macrophages containing gram negative bacteria in the lamina propria. Clinical signs: diarrhea, sometimes bloody --\> ematiation

Answer 89

Causes diarrhea in calve. Usually associated with other etiology (corona, rotovirus) Will see protozoal organism (basophilic blebs) on the apical surface of the enterocyte causes a reduced absorptive surface --\> diarrhea ZOONOTIC!!!!!

Answer 90

Coccidial enteritis In sheep and goats, it causes hyperplasia of the mucosa --\> grey raised nodules

Answer 91

Coccidia parasitize epithelial cellls of the intestines--\> deaht of cells --\> necrophemorrhagic enteritis. Clinical Signs: bloody diarrhea, loss of condition, hypoproteinemia. Proliferative enteritis in goats and sheep. Male parasites will be blue, and females will be red on stain.

Answer 92

Canine Hookworms Blood sucking parasites that cause significant anemia and hypoproteinemia in puppies Larvae may be found in colostrum.

Answer 93

ANOPLOCEPHALA PERFOLITIA Cause issues at the ileocecal valve --\> ilial hypertrophy --\> colic

Answer 94

Whipworm Parasitize the cecum and colon of domestic animals. Most infections are subclinical Severe infections may lead to bloody diarrhea, weight loss, dehydration and anemia.

Answer 95

"Milk spot liver"= fibrosis of the conntective tissue capsule and periportal fibrosis. Etiology: \***Ascaris suum** & renal worm (**Stephanurus dentatus**) Ascaris suum is most common Stephanurus dentatus is common in free-range pigs in St. Kitts.

Answer 96

**Dogs and cats** Most primary tumors are carcinomas

Answer 97

Carcinomas

Answer 98

Lymphosarcoma (LSA) The alimentary form of LSA has the highest incidence in cats.

Answer 99

Lymphosarcomas in the intestines are usual manifestation of multicentric lymphosarcomas. The exceptions may be in cats, in which the alimentary form of lymphosarcomas are primarily from the intestines.

Answer 100

25% cardiac output 67% portal vein / 33% hepatic artery

Answer 101

In necropsy, to determine if the liver size is abnormal. Carnivores 3-4% body weight Omnivores 2% body weight Herbivores 1% body weight (NO NOT MEMORIZE %)

Answer 102

**Bile ductules (3-4) Branches of portal vein Hepatic artery Nerves and lymphatics**

Answer 103

portal triad --\> central toxic injury near portal triad hypoxic injury near central vein

Answer 104

central vein --\> portal triad bile ducts

Answer 105

Zone 1 or **centroacinar (periportal)** surrounds the portal triads Zone 2 or **midzone** is the intermediate or midlobular area Zone 3 or **periacinar (centrilobular)** surrounds the central veins

Answer 106

Hepatocytes!

Answer 107

regional macrophages participate in immune and regenerative response

Answer 108

produce and maintain entracellular matric and store vitamin A Ito cells play role in fibrosis (drug target)

Answer 109

1. Bilirubin metabolism 2. Bile acid metabolism 3. Carbohydrate metabolism 4. Lipid metabolism 5. Xenobiotic metabolism 6. Protein synthesis 7. Immune function

Answer 110

Clinical signs appear after approximately **75%** of the parenchyma is injured **Liver enzymes** (AST, ALT, LDH, alkaline phosphatase, gammaglutamyl transpeptidase) can be **elevated early;** thus they are commonly used as **biomarkers of liver injury**

Answer 111

1. Hematogenous 2. Retrograde through biliary and pancreatic ducts 3. Direct extension through the liver capsule (example: trauma through the abdominal wall, rib cage, lumen of the gastrointestinal tract)

Answer 112

1. Metabolic bioactivation of chemicals to reactive species 2. Stimulation of autoimmunity 3. Stimulation of apoptosis 4. Disruption of calcium homeostasis 5. Canalicular injury 6. Mitochondrial injury

Answer 113

* Atrophy (whole organ, individual cell) * Hypertrophy and hyperplasia * Regeneration of parenchyma * Replacement by fibrosis * Biliary hyperplasia

Answer 114

Increased catabolism /Decrease anabolism (ie portal shunt) Decreased blood flow Decreased bile flow Pressure

Answer 115

**Oval (stem) cells** can differentiate into hepatocytes or bile duct epithelium

Answer 116

1. Intact framework (reticulum fibers) 2. Good blood supply 3. Patent bile ducts

Answer 117

Hepatocellular regeneration due to sustained or repetitive hepatocellular injury is often nodular. Histolofically looks like an unorganized cluster of cells, lacks a capsule. Surrounding area in pucture also has bile duct hyperplasia due to response to injury

Answer 118

* Increased amount of connective tissue within the liver * Ito (stellate) cells also proliferate • **Significance is dependent upon effects on normal hepatic function** and type of collagen (removal and remodelling)

Answer 119

End stage liver / Liver Cirrhosis In cases of chronic injury, regeneration can result in hepatocellular nodular proliferation/regeneration with fibrosis (post-necrotic scarring) between nodules and impaired blood and bile flow. Liver usually reduced in size

Answer 120

Severe **bilary hyperplasia**

Answer 121

**Capsular fibrosis/perihepatitis in horses (incidental lesion)** _Due to:_ Resolution of peritonitis, Parasitic migration, friction • Also known as **“perihepatitis filamentosa”**

Answer 122

Focal areas of pale discoloration **Adjacent to mesenteric attachment= incidental** Seen occasionally in **cattle and horses**

Answer 123

Rupture etiology: Trauma or Enarged Liver Sequela: death due to **hemoperitoneum** -or- healing by **spider web fibrosis** (picture)

Answer 124

Occur rapidly- especially if hot environment Pale, irregular foci Greenish black discoloration near the intestine Emphysema Liver autolysis will make your histology slides crappy

Answer 125

1. **Random** (Single cell, Multifocal, Piecemeal necrosis) 2. **Zonal** 3. **Massive**

Answer 126

**Random, multifocal** liver necrosis Size: Etiology: Infections= bacterial (pig salmonellosis), viral (equine herpes), parasitic.

Answer 127

**Centrilobular or Zone 3/ periacinar** necrosis commonly due to **hypoxia**

Answer 128

**Midzonal/Zone 2 necrosis** Very **rare.** Seen in yellow fever.

Answer 129

**Periportal** necrosis Common Etiology= **toxic**

Answer 130

necrosis that involved entire lobule or contiguous lobules can be caused by hepatosis dietica in swine (vit E/ selenium deficiency)

Answer 131

Associated with Vitamine E/Selenium deficency and generation of free radicals. One of the most common causes of massive hepatic necrosis. May see jaundice and complete necroisis of nodule (seperated by prominant CT)

Answer 132

Congenital cyst Developmental abnormality

Answer 133

**Congenital bilary cyst** Due to abnormal development of bile ductules - cyst will have a thin wall, lined by a single layer of **bilary epithelium** Usually an ***incidental finding***

Answer 134

**CONGENITAL POLYCYSTIC LIVER DISEASE** Multiple cysts are located in the liver and kidney. Can cause pressure necrosis of the surrounding parenchyma. **Cair terriers, West Highland white terries,** and **Persian cats** are predisposed. May result in *mortality* due to liver or renal failure. NOT incidental (compared to incidental bilary cysts)

Answer 135

Cair terriers West Highland white terries Persian cats

Answer 136

**Diaphramatic hernia of the liver** Congenital abnormality due to missing part of the diaphram or a very thin wall of the diaphram. (could also be traumatic)

Answer 137

CONGESTION Infarction/ischemia are rare due to high collateral circulation and double circulation (arterial and portal vein)

Answer 138

Slight enlargement of the liver Prominant reticular pattern- due to congestion of centrilobular areas

Answer 139

**"nutmeg liver"** - due to right sided heart failure (picture) **Reticular pattern** due to zonal congestion

Answer 140

Congestion around central veins Hepatocytes around portal areas are often unremarkable Midzonal fatty change is occasionally seen

Answer 141

_Budd-Chiaria syndrome_= **hepatomegaly, ascites,** and **abdominal pain**. It is caused by **thrombosis of the hepatic vein** and the adjacent inferior vena cava. Probable causes of thrombosis include conditions producing thrombotic tendencies or sluggish flow such as myeloproliferative disorders, infections, trauma and neoplasia.

Answer 142

Blood within the portal venous system bypass the liver and drain into the posterior vena cava, or the azygous vein. _Gross:_ * Hepatic encephalopathy and ascites are seen in congenital cases in dogs and cats. * Decrease size fo the liver because it has been deprived of primary perfusion by portal hepatotrophic factors such as insulin, glucagon and amino acids.

Answer 143

Small hepatocytes Portal veins are small/abscent in small portal triads Multiple, more prominant, hepatic arterioles

Answer 144

Acquired shunts have multiple, thin walled and tortuous blood vessels and evidence of liver disease Due to chronic portal hypertension..

Answer 145

**Telangiectasis** _Definition_: presence of focal areas in which sinusoids are dilated and filled with blood. _Gross appearance_: irregular, circumscribed, dark-red foci of cavernous ectasia of sinusoids. _Common in_: cattle and old cats _Clinical Signifigance_: NONE! _Histologically_: Dilation of sinusoids

Answer 146

**Telangiectasis**= focal areas of silated sinusoids within the liver NO clinical significance Also commonly seen in older cats (picture)

Answer 147

Cattle and older cats No clinical signifigance. Focal dilitation of the sinusoids of the liver. Grossly appear as irregular dark red foci.

Answer 148

1. **_Excessive entry of fatty acids into the liver_** * consequence of (1) **excessive dietary intake** of fat or (2) **increased mobilization of fat** from adipose tissue due to **increased demand** (lactation, starvation, and endocrine abnormalities). 2. **_Decreased oxidation of fatty acids within hepatocytes_**. 3. **_Increased esterification of fatty acids to triglycerides._** 4. **_Decreased apoprotein synthesis_** * **__**subsequent decreased production and export of lipoprotein from hepatocytes. 5. **_Impaired secretion of lipoprotein_** from the liver

Answer 149

Enlarged heavy **uniform light yellow or orange** cuts with ease greasy **rounded edges** smooth surface tissue will **float** in water or fixative

Answer 150

Mdx: Diffuse hepatic lipidosis Condition: Hepatic lipidosis

Answer 151

(1) **Oil red O** - have to do a frozen stain, normal processing will wash fat out of cells. (2) **Osmium tetroxide**- binds to lipids and keeps them within cells. Prevents washing out during normal processing. Lipids will appear black. _VERY BAD FOR THE ENVIRONMENT_

Answer 152

Depends on the cause, severity and duration. * Lesion is reversible in mild cases * could lead to hepatic necrosis, fatty cysts, fat embolism and liver rupture with internal hemorrhage. * Fatty livers are also more susceptible to toxic damage and traumatic injury.

Answer 153

* _Physiological Fatty Liver_ ( late pregnancy, peak lactation, dietary excess, **TWINE PREGNANCY IN EWE**S) * _Fasting in obese animals_ __ * _Bovine fatty liver syndrome_- occurs in obese dairy cattle a few days after parturition when another event causes them to go off feed. * _Feline fatty liver syndrome_- poorly defined/ideopathic. In either obese or anorexic cats. Causes icterus, hepatic failure and hepatic encephalopathy (picture) * _Equine hyperlipemia_ - occurs in obese ponies od shetland breed. Pathogenesis unknown. See pale discoleration and rounded edges of liver * _Endocrine disorders_ * _Toxic and anoxic injury_

Answer 154

**_Equine hyperlipemia_** Common in **obese Shetland breed ponies** Unknown pathogenesis \*\*Pale discoloration and rounded edges\*\*

Answer 155

**diabetes mellitus** and **hypothyroidism**. The increased lipolysis results in increased access of fatty acids, coinciding with shortage of ATP (due to reduced glucose availability), concluding with **reduction in lipoprotein synthesis.**

Answer 156

**Accumulation of fat** within cells arising as a **consequence of cellular injury** is called fatty degeneration. Injury to hepatocytes can lead to accumulation of fat because of decreased formation and/or export of lipoproteins by hepatocytes and decreased oxidation of fatty acids within hepatocytes

Answer 157

Diabetes mellitus Hyperadrenocorticism (**steroid induced hepatopathy**) Glycogen storage diseases

Answer 158

Glucocorticoids induce **glycogen synthetase** and enhance hepatic storage of glycogen --\> excess accumulation --\> swelling

Answer 159

_Gross_: Enlarged, pale liver due to swollen hepatocytes (particularly in the midzonal areas) * Differential diagnosis is hepatic lipidosis/ fatty change; thus a special stain **(PAS stain)** should be used to distinguish these two conditions. _Histologically_: "feathery" cytoplasm. Glycogen accumulation around a centrally located nucleus. Enlarged cells. Confirm with **PAS** stain

Answer 160

Abyssinian cats Siamese cats Chinese Shar-Pei dogs

Answer 161

Space of Disse

Answer 162

Hepatic amyloidosis usually occurs as a consequence of **prolonged antigenic stimulation such as chronic infection or repeated inoculations of an antigen.**

Answer 163

Amyloid: Congo Red Glycogen: PAS Lipid: Oil Red O Copper: Rhodanine or Rubeanic acid

Answer 164

* Dietary excess in ruminants * Grazing on pasture low in molybdenum (common in ovine) * Hepatic (cholestatic) disease (accumulates in bile --\> injury) * Chronic liver disease * Hereditary disorders (Bedlington and West Highland terriers, Dalmatians , cats, LEC rats)

Answer 165

**Bedlington** and **West Highland terriers** **Dalmatians.** Also reported in cats **Long Evans Cinnamon (LEC)** rats are human model for Wilson's disease

Answer 166

**Hematogenous/** blood-borne route (most common) **Ascending route**: reaching the liver by ascending the biliary system Direct extension from the **peritoneum**

Answer 167

inflammation of bile ductules and liver parenchyma

Answer 168

Etiologic diagnosis: Parasitic hepatitis. Etiologic agent: ***Fascioloides magna***

Answer 169

**HERPES VIRUS** Discrete off-white foci are seen in young animals and fetuses with Herpes viruses. Necrotic hepatocytes often contain **intranuclear inclusion bodies (INIB)** and are surrounded by inflammatory cells. _Agents include:_ * Bovine Herpes virus 1: **Infectious Bovine Rhinotracheitis (IBR)** * Equine Herpes virus 1: **Equine Viral Rhinopneumonitis (EVR)** * **Canine herpes virus 1** * **Pseudorabies** in pigs.

Answer 170

**Canine adenovirus 1= Infectious canine hepatitis (ICH)** AKA Rubarth’s disease, Fox encephalitis, *Hepatitis contagiosa canis* Highly contagious **peracute disease** See **intranuclear inclusion bodies** _Pathogenesis_: Oral exposure to urine → tonsilitis → viremia → virus has tropism for hepatocytes, vascular endothelium, renal epithelium, and mesothelium _Clinical signs_: peracute onset, with vomiting, diarrhea, petechia in mucosal surfaces, hemorrhagic diathesis (=excessive bleeding)

Answer 171

* *Periacinar individual cell necrosis** of hepatocytes * *Intranuclear basophilic inclusion bodie**s in hepatocytes, endothelial cells, biliary epithelium and Kupfer cells * *Endothelial damage** in various organs * *Minimal inflammation** (peracute)

Answer 172

Equine serum hepatitis aka Theiler's disease Caused by **Pegivirus** (used to be ideopathic) Disease usually occurs 1-2 months after injection with a biological products of equine serum origin e.g. pregnant mare serum or tetanus antitoxin, but can occur without any such inoculation. Clinical signs are acute even though liver lesions may appear older. Characterized by icterus, ascites, petechiae, and hepatic encephalopathy due to severe hepatic fatty degeneration and some necrosis, cholestasis, mononuclear infiltration and slight fibrosis and regeneration.

Answer 173

**Bacillary hemoglobinuris** Caused by ***Clostridium haemolyticum*** which produces a **B toxin.** Occurs in cattle and sheep when the liver is injured. (ie. Migrating liver flukes create an anaerobic environment for latent spores of the organism to germinate and elaborate the toxins.)

Answer 174

**Black disease/ Infectious necrotic hepatitis** caused by ***Clostridium novyi* type B** Dark discoloration of skin is due to severe sub-q venous congestion lesions of fluke infestions or migration through the liver are also associated with it

Answer 175

Caused by ***Clostridium piliforme*** (previously known as Bacillus piliformis) .It causes **multifocal necrotic hepatitis and colitis.** Diagnosis is done by demonstrating bundles of large, long bacilli in hepatocytes stained with **silver (Warthin-Starry) stain**. Seen especially in **rodents** and immunocompromised or **very young animals** (foals, calves, kittens, puppies)

Answer 176

**Tyzzers disease- *Clostridium piliforme*** Diagnosis is done by demonstrating bundles of large, long bacilli in hepatocytes stained with silver **(Warthin-Starry) stain.**

Answer 177

Disease characterized by **jaundice** Pathogenesis varies according to serotype of Leptospira sp.. Lesions are often due to **ischemic injury following hemolytic anemia.** **Cholestasis** has also been implicated as a cause of icterus ***Leptospira grippotyphosa*** has also been associated with chronic active hepatitis in dogs. Demonstrate lepto via silver stain (warthin starry)

Answer 178

hematogenous infection or **_secondary to omphalophlebitis_** seen in _cattle_ as a complication of **chemical rumenitis or traumatic reticulitis.** Abscesses may be few or many and are usually caused by mixed bacterial flora including ***Fusobacterium necrophorus***, ***_Trueperella pyogenes_*** (formerly known as Arcanobacter pyogenes), ***Streptococci*** and ***Staphylococci*.** The **left lobe** is more frequently affected. Use NAG- neoplasia, abcess or granuloma

Answer 179

Could be **incidental finding** at abattoir or necropsy **May heal, become encapsulated and sterile** May cause focal **adhesive peritonitis, or diaphragmatic adhesions** (photo) May break into hepatic vein or vena cava and cause **thrombophlebitis, endocarditis, pulmonary abscesses or massive endotoxic shock** **Generalized infection** in young animals **Toxemia** if numerous.

Answer 180

Occurs secondary to fungal infections (Blastomycosis, Histoplasmosis), bacterial diseases such as tuberculosis (confirm via acid fast stain)

Answer 181

Mycotic infection of the liver Usually seconday to mycotic ruminitis in cattle or part of a systemic mycosis Have red rim, but no campule _Etiology:_ Aspergillus fumigatus and other Zygomycetes in ruminants Histoplasma capsulatum Cryptococcus neoformans Coccidioides immitis Sporothrix schenckii

Answer 182

***Fasciola hepatica*** Larvae migrate through the liver and matureflukes reside within the bile ducts Prominennt areas of bile duct, due to inflammation and fibrosis, may look like cords. Causes **chronic fibrosing cholangitis**

Answer 183

*Fasciola hepatic* causing chronic fibrosing cholangitis that looks like cords

Answer 184

Hydatid cysts/ intermediate stage of ***Ecchinococcus granulosus*** Dog is the definitive host.

Answer 185

Proliferative cholangitis Etiology: Eimeria stiedae Gross appearance: multiple, raised, off-white nodules scattered throughout the liver

Answer 186

Etiology: ***Histomonas meleagridis*** Disease name: **Black head** Pathogenesis associated to ***Heterakis gallinarum*** MDX: **Multifocal granulomatous hepatitis ("target lesion")** and Diffuse granulomatous typhilits

Answer 187

It is a hepatotoxic plant. **Microcystin** is the main preformed toxin. It blooms in late summer or early fall _Lesion include_: * *Acute hemorrhagic gastro-enteritis** * *Acute centrilobular to massive hepatic necrosis** * *Chronic liver disease** in survivors

Answer 188

**Pyrrolizidine alkaloid toxicity-** due to alkaloids being convered to toxic pyrrolic esters by the liver p450 system, Common in cattle, horses, pigs, goats, sheep _Gross_: Hepatopathy * Acute: periacinar necrosis * Hepatic veno-occlusive disease * Chronic with fibrosis (most common form) \*\*\*\*_Histology_\*\*\*\*\*\* * **Portal fibrosis\*** * **Biliary hyperplasia\*** * **Megalocytosis\*\*** (toxin is antimitotic) * Absent parenchymal regeneration

Answer 189

Toxin plant in north america Causes Chronic liver disease and photodynamic dermatitis _Histology_: **Fibrosis, bile duct hyperplasia, & portal hepatitis** _NO_ megalocytosis

Answer 190

A. _Aflatoxins-_ **B1** is most common and potent (carcinogen). Chronic \> Acute B. _Sporidesmin-_ toxic to bile duct epithelium --\> cholangiohepatits. **Photosensitization & facial edema in sheep** C. _Phomopsin_- grows on lupins, chronic liver damage in herbivores D. _Poisonous mushrooms_- dogs, fatal acute periacinar to massive hepatocellular necrosis

Answer 191

Sheep Cu accumulates in liver lysosomes and is release as a consequence of stress--\> lipid peroxidation and massive hepatic necrosis

Answer 192

**• Trimethoprim-sulfonamid**e - Doberman pinschers • **Carprofen** - especially Labrador retrievers **• Ivermectin** - collies and shelties NO **• Anticonvulsants:** primidone, phenytoin and phenobarbital

Answer 193

Manifestation of liver dysfunction and failure --\> depression, behavior changes, mania, convulsions, head pressing _Causes_: Acute liver disease- horse and ruminants Portosystemic shunts - dogs and cats Chronic liver disease - any animals _Pathogenesis:_ Blood accumulation of neurotoxic substances bypassing the liver Requires shunting of \>10-15% of portal blood Main toxic substance is ammonia **Ammonia bypasses the liver\*\*→ increased levels reach the general circulation → go through the blood-brain barrier causing encephalopathy.**

Answer 194

1. 1. Overproduction of bilirubin (**prehepatic jaundice)** * Hemolysis - intra- or extra-vascular 2. Decreased uptake, conjugation or secretion of bilirubin **(hepatic jaundice**) * Severe hepatocellular injury * Impairment of flow within canaliculi (intrahepatic cholestasis) 3. Reduced outflow of bile in extrahepatic bile ducts and gallbladder **(post hepatic jaundice)** * Mechanical obstruction of bile ducts (extrahepatic cholestasis) or gallbladder (cholelithiasis)

Answer 195

* **Hemorrhagic diathesis or bleeding tendencies** • Impaired synthesis of clotting factors • Reduced clearance of products of clotting cascade • Impaired platelet function • Impaired absorption of vitamin K • Disseminated intravascular coagulation (DIC) * **Hypoalbuminemia** • Decreased synthesis in chronic liver disease • Loss in ascites or via the gastrointestinal tract

Answer 196

Acquired portosystemic shunts

Answer 197

**Hepatocutaneous syndrome (Superficial necrolytic dermatitis)** A rare cutaneous problem in liver disease in dogs

Answer 198

Photosensitization is due to activation of photodynamic pigments by UV light 1. **_Primary_**  St John’s wort (Hypericum perforatum)  Chlorpromazine  Phenothiazine 2. **_Secondary_** (hepatogenous) • Occurs in herbivores with impaired excretion of phylloerythrin • Is the **most common form** 3. **_Congenital_** • Abnormal metabolism of heme --\> Retention of porphyrins

Answer 199

**Hepatocellular nodular hyperplasia** - age related change only in _dogs_ Regenerative nodules Bile duct hyperplasia

Answer 200

benign hepatic tumor of bile epithelium common in cats

Answer 201

**Hepatocellular Adenoma**= beinign neoplasm of hepatocytes Seen in young ruminants s a single, non-encapsulates, red-brown nodule. It is composed of **well differntiated hepatocytes** and the portal arease are _NOT_ seen in the neoplastic ares

Answer 202

**Hepatocellular Carcinoma = Malignant** • Most often seen in _dogs_ _Gross_: solitary and involes entire lobe. Cut surface is multilobulated and grey-white to yellow brown _Histology_: cells are arranfes in a **trabecular pattern** (3 or mor cells thick). Hepatocytes exhibit atypical and bizarre forms

Answer 203

**Cholangiocellular adenoma-** Benign tumour arising from the bile ducts. Often cystic **Cholangiocellular carcinoma-** Relatively common (described in all species) • Multilobulated, **_firm_**, raised, with central areas of depression (umbilicated).

Answer 204

Hemangiosarcomas are **mesenchymal** origin tumors that arise from the **right atrium** Animals die when the tumor ruptures

Answer 205

1. **Tissue Collection** 2. **Fixation-** **10% NBF** at **10:1** NBF:tissue. Fixes at **~1 mm/hour** for 24 hours 3. **Trimming**- lesion & normal. All layers. ~3mm thickness 4. **Processing-** replace water with wax. Alcohol --\> **xylene** --\> paraffin. 15 hours 5. **Embedding-** create mold by putting in paraffin filled block then place on ice. 6. **Microtomy-** rough trim before then cut into 2-10 um (4um) 7. **Staining-** deparaffinize via xylene, alcohols and water befor staining 8. **Coverslipping**

Answer 206

~3mm thick ensure it fits in the cassette without smushing it

Answer 207

Use **10 % NBF** at **10:1** ratio of NBF:tissue It fixes at a rate of **~1mm/hour**, so ensure pieces are small Have tissue in fixative for 24 hours. You may need to change out fixative if feces or blood within

Answer 208

embryo= yolk sac gestation= liver, spleen --\> bone marrow

Answer 209

Neutrophils= hours Platelets= days RBC= months

Answer 210

Release of immature cells indicates **bone marrow stress or disease** Under normal circumstances only mature cells are released into the systemic circulation Hematopoiesis is controlled by soluble stimulatory factors that include cytokines, hormones and growth factors

Answer 211

1. Unexplained **cytopenias** (any non‐regenerative anemia) 2. **Maturation defects or morphologic abnormalities** in cells 3. Potential **myeloproliferative/lymphoproliferative** disease 4. Potential **malignancies metastatic** to marrow

Answer 212

**aspirates** (cytology) **Core biopsies** (histology)- more invasive but you can see cell organization

Answer 213

Nothing! The bone marrow is normally this color in neonates due to the bone marrow being active Ex. normal 13 day old foal (picture below)

Answer 214

**_Serous atropy of Fat_** Due to **starvation of cachexia** (caused by disease, inflammation, diet, neoplasia, etc) Also will see serous atropy of fat at the base of **heart** and around the **kidney.** Common in sheeps and goats May aslo see osteopenia (picture)

Answer 215

1. **Radiation** 2. **Chemical, antineoplastic drugs** 3. **Viral infections** (parvovirus of feline panleukopenia, canine parvovirus, EIA virus etc.) Since bone marrow cells are very active metabolically, a variety of insults can interfere with hematopoiesis. Bone marrow necrosis may result in **pancytopenia**. [Parvoviruses- infect rapidly dividing cells. In-utero infection in cats causes cerebellar atrophy. Infects cardiomyocytes of puppies.]

Answer 216

**Suppurative osteomyelitis** is usually the result of **bacterial infections**. Tissue will be rich in neutrophils and macrophages. Septic osteomyelitis= comes from the blood (maybe originating from the umbilical cord/omphalitis)

Answer 217

Diffuse granulomatous osteomyelitis is usually the result of **fungal infections, e.g.: _histoplasmosis_ and _coccidiodomycosis._** Osteomyelitis may result in Pancytopenia Lesion will be rich in macrophages that may contain the causative agent . Multifocal granulomatous osteomyelitis is seen in tuberculosis of birds(?) **Histoplasmosis** can also manifest in other organs as a diffuse granulomatous uveitis, hepatitis and splenitis.

Answer 218

*Cytauxozoon felis* – **protozoa** Often _fatal_ **Bobcats (**Lynx rufus) are the reservoir _Two forms_ 1. **Schizogenous phase** --\> **macrophages** (enlarged and filled with parasite) --\> systemic illness 2. **Erythrocytic phase** --\>**anemia**

Answer 219

* Decreased proliferative activity * Usually characterized by increase in yellow marrow * Often accompanies marrow degeneration. * Sequel will depend on cell line(s) affected Example: marrow damage secondary to feline panleukopenia virus infection. Example: myelofibrosis (CT replaces precursors) in scirvey/Vitamin C deficiency

Answer 220

* **myelophthisis,** the replacement of myeloid tissue by abnormal tissue: * collagen‐rich fibrous connective tissue(myelofibrosis) * malignant neoplasia * **abnormality of hematopoietic cells** – aplastic anemia/pancytopenia (destruction of hematopoietic stem cells)

Answer 221

One or multiple cell lines may be hyperplastic depending on the stimulus _Gross finding_: **Red marrow replacing yellow marrow (fat)** at metaphysis and endosteal surface of diaphysis. _Pathogenesis_: ↓cell numbers in blood caused by **increased peripheral demand**; or adequate numbers of **hypofunctional cells** in peripheral blood --\> lead to ↑cell production in the marrow in response to poietns and interleukins. _Example:_ Bovine Leukocyte Adhesion Deficiency (BLAD) syndrome - in people and dogs (Irish setters). Defect in migration of leukocytes. horse w/ hyperplasia due to IHA (picture below)

Answer 222

**Bone marrow hyperplasia secondary to EIA** Causes of anemia in EIA (1) extravascular immune mediated hemolysis (2) decrease production (3) Inflammation May see acute thrombocytopenia (due to immune mediated mechanism, they are innocent bystanders) Horses are infected for life with EIA. They act as reservoirs. the disease can be transmitted by flies and mosquitoes.

Answer 223

**Lymphoproliferative (LYMPHOID) Disease** Marrow and/or extramedullary neoplastic transformation of a lymphoid cell line * lymphoma (lymphosarcoma) * lymphoid (lymphocytic) leukemia * plasma cell tumors Myeloproliferative (MYELOID) Disease are rarer.

Answer 224

1. **Lymphoid leukemia** 2. **Lymphoma** (Leukemic phase) 3. **Plasma cell neoplasia** ( multiple myeloma & plasmacytoma)

Answer 225

**Acute forms:** rapidly fatal and tend to occur in younger animals, poorly differentiated cells, decrease number of circulating cells **Chronic forms:** longer clinical course (indolent), neoplastic cells are relatively well‐differentiated, increase number of circulating cells

Answer 226

* **Anemia** * **Hypercellular marrow** * **Leukemic cells in peripheral circulation** (especially if chronic) * **Megaloblastic alterations** in erythroid cells * **Thrombocytopenia** (not always present) * **Hepato/splenomegaly** – Myelo/lymphoproliferative disease spreads early to involve the spleen and liver. Animals may present with splenomegaly and/or hepatomegaly

Answer 227

**_Hepatosplenomegaly_** Due to **myelo/lymphoproliferative disease (LSA)** due to the early spread of these diseases to the spleen and liver Also may see anemia, hypercellular bone marrow, leukemic cells in peripheral circulation, megaloblastic alterations in RBC etc.

Answer 228

Lymphoid leukemia or leukemic lymphoma May see focal to multifocal whitish masses, that may be hard (picture below)

Answer 229

1. **Multiple myeloma**- malignant, from bone barrow, M protein, increase Ig secretion, punched out appearance, monoclonal gammopathy, hypercalcemia 2. **Cutaneous Plasmacytomas**- benign 3. **Extramedullary Plasmacytoma** - malignant, dogs, cats, horses, + amyloidosis

Answer 230

rare, malignant tumor of plasma cells that arise from the bone marrow have increase secretion of Ig/Ig subunits ( **M protein**) - monoclonal gammopathy **_"punched out" appearance of osteolytic lesions_** in 25-66% of cases. Starts in active marrow (vertebral bodies, flat bones, pelvis) hypercalcemia due to osteolysis Plasma cells will be enlarged, have perinuclear clearing, with nucleas pushed to the side due to increased cytoplasm.

Answer 231

Cutaneous Plasmacytomas- Rare ‐ usually **benign** – skin or mucous membranes Extramedullary Plasmacytoma- Rare – **malignant** – dogs, horses, cats; **Amyloidosis** is a feature Both are types of plasma cell neoplasias

Answer 232

Multiple Myeloma "punched out" osteolytic lesions

Answer 233

1. **_Histiocytic sarcoma_ -** uncommon – **malignant** tumor of histiocytic (macrophage or dendritic cell) origin * frequently in the dog (**Rottweiler, Bernese mountain dog**); rarely in cat * disseminated form= “malignant histiocytosis” 2. **_Cutaneous histiocytosis and systemic histiocytosis_** * **__****nonneoplastic** canine immunoregulatory disorders 3. **_Canine cutaneous histiocytoma_**- **benign** – epidermal Langerhans cell origin. "top heavy" nodular lesions. 4. **_Feline progressive histiocytosis_** • Initially indolent cutaneous neoplasm; probably of dendritic cell origin

Answer 234

Myelodysplastic (MDS) It is seen in cats infected with FeLV

Answer 235

**Red**= blood **Black** = anthracosis/carbon, tatoo ink **Brown=** melanin, parasite hematin, hemosiderin **Green**= eosinophils, blue-green algae **Orange**= paratuberculosis in sheep

Answer 236

hemorrhage

Answer 237

outer cortex=**follicular** hyperplasia inner cortex= **lymphocyte/diffuse** hyperplasia

Answer 238

buboes (bubos)

Answer 239

toxoplasmosis, salmonellosis, tularemia, yersiniosis, Tyzzer’s disease, FIP

Answer 240

**Strangles**- ***Streptococcus equi* ssp *equi***

Answer 241

Bastard strangles

Answer 242

**Caseous lymphadenitis** ***Corynebacterium pseudotuberculosis*** See concentric **"onion ring" lymph node** & eosinophilic (green) pus becomes caseous with age

Answer 243

***Mycobacterium bovis***

Answer 244

**PMWS- Porcine Multisystemic Wasting Disease** **Porcine Circovirus 2** Lymph node will be increased in size and have uneven color. Will have B & T Cell depletion --\> immunosuppresion **Botryoid intracytoplasmic inclusion in macrophages**

Answer 245

Cats | (dogs are usually healthy)

Answer 246

FeLV , BLV

Answer 247

**Multicentric**

Answer 248

B-cell lymphomas

Answer 249

FALSE _**Small** cell lymphomas_ with **low** mitotic rates are slower to progress but response poorly to chemotherapy L_arge cell lymphomas_ with high mitotic rates **rapidly progress** but response **well** to chemotherapy

Answer 250

ALL ages and ALL breeds

Answer 251

**BLV- bovine enzootic leukosis** The hemorrage and necrosis is characteristic of rapid growing tumors

Answer 252

**enzootic leukosis (BLV)** with abomasal involvement

Answer 253

**Lymphoma** It is the most common reported malignancy in pigs

Answer 254

**CATS** Lymphoma is the most common hemopoietic neoplasm in cats FUN FACT: Although it can be caused by FeLV, as FeLV infection rates has gone down the incidence of lymphoma has actually increased (**mainly gastrointerstinal lymphomas)**

Answer 255

Different types of tumors are located in different areas of the GI tract. A single biopsy of one area will commonly miss the tumor. Ex. B cell lymphomas are "further down" than T-cells, or are in the stomach.

Answer 256

**_False_- they dont have lymph nodes**...

Answer 257

Marek's (herpesvirus)

Answer 258

**Marek's disease (Herpesvirus)**

Answer 259

lymphoid atropy

Answer 260

nodule , bloody

Answer 261

1. Splenic nodular hyperplasia 2. Fibrohistiocytic nodules 3. Primary neoplasms 4. Secondary (metastatic) neoplasms 5. Granulomas 6. Abscesses

Answer 262

false they lack the proper blood suppy

Answer 263

Siderotic plaques

Answer 264

Siderofibrosis of the splenic capsule (siderotic plaques/nodules, Gamma‐Gandy bodies).

Answer 265

aging/degenerative , hemorrhage

Answer 266

Hemosiderosis (degenerative lesion) pigment make it look brown

Answer 267

Acute passive congestion

Answer 268

acute-passive congestion

Answer 269

Classical Swine Fever (hog Cholera)

Answer 270

Splenic rupture

Answer 271

Splenic hematoma

Answer 272

Aleutian disease of mink and ferrets Equine infectious anemia Due to Chronic antigenic stimulation results in hyperplasia of the monocyte‐macrophage or lymphoid/ plasma cell population

Answer 273

Bacillus anthracis large bacillus, forms short chains and is characterized by square ends and a distinct capsule.

Answer 274

lymphoid hyperplasia

Answer 275

***Francisella tularensis*** (Tularemia) - "rabbit fever"

Answer 276

Herpes "herpes inclusion body disease (hepatosplenitits) of raptors" Raptors get infected by consuming pigeons infected (often subclinically) with columbid herpesvirus (CoHV),

Answer 277

***Mycobacterium avium***

Answer 278

**Nodular hyperplasia** Incidental - slow growing likely an aging change, formed by a mixture of hyperplastic extramedullary hemopoietic cells, and are prone to rupture from trauma, resulting in hemoabdomen and exsanguination

Answer 279

hemangiona

Answer 280

Hemangiosarcoma (they are also commonly found on the skin) Highlt metastaitc, invade the abdominal cavity.

Answer 281

Lymphosarcoma

Answer 282

Histocytic sarcoma

Answer 283

EHV-1 FeLV BVD Canine Distemper

Answer 284

hypoplasia

Answer 285

Thymic Lymphoma Results in lung collaps, breathing difficulties and compression of vessels feeding the brain. Poor prognosis, hard to remove.

Answer 286

1. **Infectious bursal disease** (birnavirus)- lymphoid depletion (3-6 weeks) 2. **Lymphoid leukosis** (avian leukosis virus) - neoplastic proliferation of B-lymphocytes 3. **New castle disease** (paramyxovirus)

Answer 287

**3-6 weeks** IBV is the most important disease of concentrated broiler producing areas of the US Causes lymphoid depletion --\> immunodeficiency due to the virus targeting pre-B lymphoctes. Birds usually die of secondary infections.

Answer 288

**Infectious bursal disease (IBD)** Other names of this condition: Gumboro disease, Avian infectious bursitis Etiology: Avian bursal disease virus (Birnavirus)

Exam 1 Path II Flashcards

(333 cards)