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2021 ACLAM Images > Rabbit > Flashcards

Flashcards in Rabbit Deck (82)
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1

Name the labeled structures

Alimentary tract from a mature rabbit, illustrating the

prominent gut-associated lymphoid tissue (GALT), including a Peyer’s

patch (A) in the wall of the ileum, the sacculus rotundus (B) at the

terminal ileum, the cecal tonsil (C) in wall of the proximal cecum, and

the cecal appendix (D) at the terminus of the cecum.

2

Name the tissue type and common cell type present.

 

GALT from a normal mature rabbit, depicting the

common presence of histiocytes filled with refractile particulate debris

within the follicular center.

3

Name the structure

Pulmonary artery of a normal rabbit. Pulmonary arteries

are highly muscular, which can be misinterpreted as muscular

hypertrophy.

4

Describe the structure and its incidence

Female reproductive tract of a normal doe, depicting the 2

separate cervices, which is typical for this species. The uterus is

bicornuate, with 2 separate horns.

5

Name the tissue, describe the lesion, name the cause

Integument from a rabbit with leporid herpesvirus 4

infection, depicting necrosis of the epidermis and papillary dermis with

underlying dermal hemorrhage.

6

describe the notable structures (arrows)

Leporid herpesvirus 4 infection of the skin from a rabbit, depicting a multinucleate syncytium and intranuclear inclusion bodies (arrows) in the follicular epithelium. 

7

 Cerebrum.  Name the structures and causative agent.

Cerebrum from a rabbit with naturally acquired herpes

simplex virus encephalitis. Note the prominent intranuclear inclusion

bodies in neurons (arrows) and astroglia

8

1) Causative agent, genus

2) Usual means of transmission

3) Potential sequalae in NZW

 

1) Cottontail rabbit papillomavirus, Kappapapillomavirus

2) Insect vectors, e.g. mosquitos and ticks

3) squamous cell carcinoma

9

Describe.  What is the most likely cause?

Solitary papilloma on the ear of a laboratory rabbit naturally infected with cottontail rabbit papilloma virus (CRPV). 

10

1) causative agent

2) means of transmission

3) potential sequale

4) describe histology

1) rabbit oral papillomavirus

2) direct contact, including does to kits

3) none - no reports of malignant transformation

4) basophilic intranuclear inclusions and viral antigen in the stratun spinosum

11

1) tissue

2) arrow

3) cause

4) associated disease

12

1) Describe the lesions

2) causative agent

 

1) Mucopurulent conjunctivitis, periocular swelling, and

facial edema (myxomatosis)

2) myxoma virus

3) family Poxviridae, genus Leporipoxvirus

13

Tissue, arrows, cause

Intracytoplasmic inclusion bodies (arrows) in the

conjunctival epithelium of a rabbit with myxomatosis.

14

tissue, pathology, cause

Lymph node, depicting hypertrophy and hyperplasia of stellate myxoma cells and severe lymphocytic depletion.

15

Rabbit respiratory epithelium with intracytoplasmic inclusions (arrows).  name the cause

Myxoma virus

16

Cause

related to

 

Rabbit (Shope) fibroma

myxoma virus

17

describe

arrows

cause

Skin of a Sylvilagus rabbit infected with Shope fibroma

virus. There is a dense network of fusiform to polyhedral fibroblasts in

the dermis, many of which contain prominent intracytoplasmic

inclusion bodies (arrows).

18

Organ, gross description, cause

Lungs from a wild Oryctolagus rabbit with acute rabbit

hemorrhagic disease (RHD) virus infection. There is marked pulmonary

edema with multifocal ecchymoses.

19

tissue, microscopic description, cause

Lung from a case of RHD in a feral Oryctolagus rabbit from Australia. Notemultiple intravascular thromboses 

20

organ, gross description, cause

Liver from a domestic rabbit naturally infected with

RHD virus. Note the granular texture of the hepatic capsule and

accentuated lobular pattern. 

21

tissue, microscopic description, cause

Liver from a rabbit experimentally infected with rabbit

hemorrhagic disease virus. Note the acute periportal and midzonal

hepatocellular necrosis. 

22

tissue, microscopic description, cause

Small intestine from a juvenile rabbit with a natural case

of epizootic rotaviral enteritis. There is submucosal edema, with

blunting and fusion of villi. Enterocytes within crypts and on villi are

immature, indicative of regeneration. 

23

tissue, microscopic description

Acute fibrinopurulent bronchopneumonia in a young

rabbit infected with Bordetella bronchiseptica. The terminal airway

and alveoli are flooded with fibrin-rich exudate.

24

Tissue

agent

distribution

stain

 

Lung of a rabbit naturally infected with cilia-associated

respiratory (CAR) bacillus. This organism colonizes the epithelium of

the larynx, trachea, and bronchi in the rabbit. Note the prominent

peribronchiolar lymphocytic infiltration (Warthin-Starry stain). 

25

Organ

description

cause

Cecum from a rabbit with clostridial enteropathy. Note

the hemorrhage and the fibrinous exudate on the mucosal surface.

26

Cecum of rabbit with Clostridium spiriforme.  Describe the tissues

Necrotizing typhlitis from a case of clostridial

enteropathy due to Clostridium spiroforme. Note the selective loss of

mucosal epithelium with relative sparing of crypts and submucosal

edema.

27

intestinal contents from a rabbit.  Name the stain, name the organisms marked by the arrow.

Gram-stained smear of intestinal contents from a rabbit

with clostridial enteropathy, demonstrating the typical coiled

appearance of Clostridium spiroforme organisms (arrow).

28

Describe

cause?

 

Acute necrohemorrhagic typhlitis in a rabbit with

Tyzzer’s disease. Note ecchymotic hemorrhages on the serosa.

29

describe

hallmark sign of?

Multifocal hepatic necrosis in an adult rabbit with

Tyzzer’s disease.

30

describe

cause?

expected histologic lesions?

Acute gastric and intestinal tympany in a rabbit that

died acutely with epizootic rabbit enteropathy. The stomach and

intestine are distended with gas and fluid, but histologic lesions are

minimal or absent in this syndrome. 

31

weanling rabbit with profuse diarrhea.  cause?

Intestine from a weanling rabbit with profuse diarrhea

associated with acute infection with an attaching and effacing

enteropathogenic Escherichia coli (EPEC). Note the fluid content that

has leaked from an incision in the small intestine (arrow).

32

organism?

Stain?

Cecum from a case of acute coliform enteritis in a

weanling rabbit. The surface mucosa is densely populated with

attaching Escherichia coli (Warthin–Starry stain).

33

describe

Hemorrhagic enterotyphlocolitis in a suckling rabbit kit

due to Klebsiella oxytoca. 

Hemorrhagic enterotyphlocolitis in a suckling rabbit kit

due to Klebsiella oxytoca. 

34

describe

cause?

Histiocytic enteritis in a laboratory rabbit associated

with Lawsonia intracellularis infection. Note the marked thickening

and rugose appearance of the serosal surface of the small intestine.

35

Jejunum of rabbit

describe

cause?

Jejunum from a laboratory rabbit with histiocytic

enteritis due to Lawsonia intracellularis infection. Villi are shortened,

lacteals are dilated, crypts are hyperplastic, and the lamina propria and

submucosa are infiltrated with histiocytes and focal accumulations of

lymphocytes. 

36

Rabbit intestinal mucosa.  stain?

Organism?

Intestinal mucosa from a rabbit infected with Lawsonia

intracellularis. Note the dense argyrophilic populations of bacteria

within the apical cytoplasm of enterocytes (Warthin–Starry stain).

37

liver of near-term doe

describe lesion

cause?

New Zealand White doe that died near-term with acute

listeriosis. There are pinpoint-size foci of hepatitis. The externalized kit

(lower left) is intact, with no evidence of maceration 

38

Tissue

describe lesion

Focal hepatitis from a case of listeriosis in a pregnant

doe. Note colonies of Gram-positive bacteria 

39

organ

cause

Pulmonary tuberculosis in a rabbit infected with

Mycobacterium tuberculosis. Rabbits develop cavitary pulmonary

lesions with frequent dissemination to other organs. 

40

Tissue

Causative agent

Small intestine of a wild Oryctolagus rabbit naturally

infected with Mycobacterium avium spp. paratuberculosis. The lamina

propria is densely infiltrated with histiocytes andmultinucleated giant cells.

41

Rabbit GALT histiocytes,

Name of organism

type of stain

Acid-fast organisms within histiocytes of the GALT of a

wild rabbit naturally infected with Mycobacterium avium spp.

paratuberculosis. 

42

Describe lesion

causative agent

Turbinate atrophy associated with chronic rhinitis due to

Pasteurella multocida infection. Note the loss of turbinates in the

affected (top) compared to the normal control rabbit (bottom). 

43

Describe lesion

Fibrinohemorrhagic bronchopneumonia and pleuritis in

a rabbit with peracute pulmonary pasteurellosis. Fibrinous exudate is

present on the pleural surface.

44

Organ

describe lesions

Pyometra in an adult doe associated with chronic

Pasteurella multocida infection. There is asymmetric distention of the

uterine horns, and the fallopian tubes are distended with purulent

exudate (right arrow). Small abscesses are scattered on the serosa (left

arrows).

45

Expected lesions in adult rabbits

histo

DDx

 Systemic staphylococcosis with focal suppurative lesions can occur in adult rabbits 

 Staphylococcal mastitis: swollen, red areas, induration of overlying skin, chronic abscess

 Respiratory tract: mucopurulent rhinitis, bronchopneumonia, and/or abscessation of the lung

 Histo: focal suppurative lesions in affected organs, w/ Gram + bacterial colonies 

 DDX: pasteurellosis, Tyzzer’s disease, and listeriosis

46

Transmission

Age predilection

 Treponema paraluis-cuniculi (formerly T. cuniculi) is a spirochete 

◦Occurs occasionally in lab rabbits, has been documented in wild rabbits in Britain

◦Seldom detected on cursory examination

 Venereal route is the most important means of spread, but extragenitalcontact transmission may occur

 Young animals may develop the disease following contact with an infected dam

 Young rabbits have been shown to be relatively resistant to the infection

47

Skin from the muzzle of a laboratory rabbit with rabbit

syphilis. Describe lesion

There is dense infiltration of the dermis with mixed leukocytes,

degeneration of epidermis, and serous exudation on the surface. 

48

Stain?

Organism

Rabbit syphilis lesion, depicting numerous spirochetes

within the surface exudate (Warthin–Starry stain).

49

Describe lesion.  

causatuve agent

Multifocal caseation necrosis in the liver of a rabbit

naturally infected with Yersinia pseudotuberculosis.

50

Tissue

Stain

Organism

Lung from a rabbit kit with pulmonary aspergillosis,

illustrating fungal hyphae (methenamine silver stain).

51

Other organs affected?

Kidney

Lung

Liver 

Heart

Cerebrum

52

Route of transmision in this case?

Breed?

 Phacoclastic uveitis and cataract formation is believed to follow transplacental infection

◦Common among dwarf rabbits, but other breeds may be affected

53

Stain?

Tissue?

Organism?

 

Encephalitozoon spores within renal tubular

epithelium and tubular lumen of a rabbit with chronic

encephalitozoonosis (Brown and Brenn stain).

54

Small intestine from a juvenile rabbit.  

Describe lesions

with acute

coccidiosis. Enterocytes contain large numbers of micro- and

macrogametocytes and oocysts.

55

Liver from a juvenile rabbit. 

Describe lesion

causative agent

Liver from a juvenile rabbit with florid hepatic

coccidiosis. In addition to the raised linear hepatic lesions, representing

involved bile ducts, the gall bladder and common bile duct are dilated

and contain flocculent material.

56

causative agent

describe histo

Hepatic bile duct of a rabbit with chronic hepatic

coccidiosis, featuring proliferative cholangitis, periportal fibrosis, and

inflammation. Bile ductular epithelium contains large numbers of

microgametocytes, macrogametocytes, and oocysts.

57

Describe cerebral lesion.  

Causative agent

Describe condition

Cerebral Baylisascaris infestation in a New Zealand

White rabbit. Note the focus of malacia and inflammation containing

multiple cross sections of ascarid larvae with characteristic lateral alae.

Larval migrans

58

Organ

Organism

Opened cecum from a domestic rabbit with Passalurus

ambiguus (pinworm) infestation.

59

Name of organism

Describe pathogenesis of lesion

Multiple Taenia pisiformis cysticerci (arrow) within the

peritoneal cavity of a rabbit.

 Cysticerosis 

◦Intermediate host stage is known as Cysticercus pisiformis

◦Ingest eggs à larvae hatch in the small intestine and migrate to the liver and blood stream

◦Cysticerci develop in the liver for a few weeks à migrate to the peritoneal cavity, where they attach to serosal surfaces

60

Causative agent

New Zealand White rabbit with Cheyletiella

parasitovorax infestation. Pruritus has resulted in patchy hair loss and

cutaneous erythema.

61

Life cycle of causative agent

Psoroptes cuniculi

 Obligate, nonburrowing parasites that chew and pierce the epidermal layers of the external ear, evoking a marked inflammatory response

 Normally spends its entire life span in the external ear of the rabbit

 Life cycle (egg to egg) is usually completed in around 3 wks

62

Describe lesion

Ears of the rabbit with scabies in the previous figure,

depicting severe hyperkeratosis. 

63

Tissue

Organism

Marked hyperkeratosis with numerous Sarcoptes mites

embedded in the keratinized debris. Note the spongiform appearance of

the keratinized epithelium due to tunneling by mites. 

64

Risk factors

 Variable morbidity, but can be high particularly in during postweaning period 

 High mortality rate 

 Rabbits 7–10 wks old are most often affected, but rabbits 5 wks to adults may be involved in outbreaks 

 Dietary factors have frequently been implicated in the pathogenesis

◦Relatively uncommon prior to the feeding of high-energy commercial rations

◦Rabbits fed high-carbohydrate/ low-fiber diet have a higher incidence of the ME than those fed diets high in fiber

65

describe lesion

Dx

massive discharge of mucin from goblet cells, with minimal or no inflammatory response

◦Colonic crypts and the lumen are distended with mucus/mucous plugs

◦Lesions are usually minimal to absent in the cecum

Mucoid enteropathy 

 

66

 Predisposing factors

 

excessive grooming and hair chewing due to boredom, insufficient dietary roughage, poor gastric motility, and a sedentary lifestyle (decreased gastric motility)

 “Outbreaks” of trichobezoars have been seen in lab rabbits raised in cold climates, and then introduced to warm indoor housing

67

Associated with

chronic exfoliative dermatosis and sebaceous adenitis.

 Associated with autoimmune hepatitis, thymoma, and cutaneous lymphoma

68

Predisposing factors

Associated organism

 Most commonly seen in heavy, mature adults

 Predisposing Factors: poor sanitation, trauma from poor-quality, wire-bottom cages, and hereditary predisposition

 Staphylococcus aureus is the most frequent bacterium isolated from lesions

69

Most common location

 Fracture site (or luxation) is usually the lumbosacral region (L7) 

70

Clinical presentation

 Observed in nonpregnant multiparous does

Associated with persistent urogenital bleeding

Necropsy: clotted blood present in the uterine lumen, w/ multiple blood-filled endometrial varices that consist of dilated, thin-walled veins 

 Varices may rupture and bleed periodically into the uterine lumen, with subsequent hematuria

 

71

underlying cause

metabolic influences

 Intestinal absorption of calcium occurs in direct proportion to dietary intake. Rabbits fed high-calcium diets e.g. alfalfa that become sick can have impaired renal absorption/excretion

◦Renal calcium resorption and excretion are in proportion to dietary intake, and regulated by parathyroid hormone, calcitonin, and vitamin D

When the resorptive capacity of the kidney is exceeded, calcium precipitates in the alkaline urine as calcium carbonate monohydrate, anhydrous calcium carbonate, and ammonium magnesium phosphate 

72

Renal interstitial amyloidosis in a chronically

immunized adult New Zealand White rabbit. 

Associated with

Other organs affected

most likely in older hyperimmunized rabbits, those w/ chronic infections (pododermatitis, pyometra), or experiment. induced 

 

73

Tissue

Condition

Cause

74

Condition

Cause

Hypercalcemic arteriorsclerosis

excessive calcium/renal overload or impairment leads to hypercalcemoia.   results in metastatic mineralization of blood vessels and other tissues, including pulmonary interstitium, and kidneys (nephrocalcinosis)

75

Hepatic lipidosis in rabbits

Mechainism

Models

Rabbits are unable to increase excretion of sterols

in the bile in response to high cholesterol in the diet, resulting in

hypercholesterolemia, hepatic lipidosis, and icterus.

NZWs fed high-cholestreol diet.  hepatopathy limits long-term experiments

Watanabe heritable hyperlipidemic syndrome homozygous rabbits - spontaneous

 

76

Copper toxicosis

Signs of acute toxicity

Histo findings - organ, stain

hemolytic anemia w/ intravasc hemolysis, splenic erythrophagocytosis, 

Hepatocytes and Kupffer cells contained blue-green cytoplasmic granules that stain positive w/ rhodanine stain

77

Age of onset

Underlying cause

Genetics

 First few weeks of life to 3–5 months of age

 Primary defect = absence or underdevelopment of the outflow channels, with incomplete cleavage of the iridocorneal angles 

Autosomal recessive allele, with incomplete penetrance

78

Genetics
condition

 

 Maxillary brachygnathia (erroneously termed mandibular prognathism)à most common genetic disorder in domestic rabbits

 Autosomal recessive

79

Morphologic changes

 coxofemoral subluxation, shallow acetabula, lateral patellar luxation, valgus deformity, and bowing of the tibia

80

Incidence

 

 

 2–3 yrs à ~4%, 5–6 yrs à ~80%

 

81

Kidneys from a young rabbit.  Multiple pale nodular masses are visible in the cortex, 

Diagnosis

Lymphoma 

Most common malignancy in juvenile and young adult rabbits

pale kidneys w/ irregular cortical surfaces (PATHOGNOMONIC)

82

Most common tumor type

carcinomas