What is the predominant leukocyte in peripheral blood of domestic rabbits?
Lymphocytes
What is the neutrophil counter part in rabbits?
Heterophil
In rabbits, what accounts for the relatively small spleen, compared to other animals?
The GALT makes up over 50% of the total mass of lymphoid tissue in the body.
Name two specialized lymphoid tissue of the gastrointestinal tract of rabbits.
Sacculus rotundus; cecal appendix
What accounts for the high calcium content in urine of rabbits compared to other mammals?
Calcium is absorbed proportional to amount in diet and not based on metabolic needs as in most other mammals. It is primarily excreted in the urine while in other mammals it is primarily excreted in the bile.
Hematuria must be distinguished from what condition in rabbits?
Normal excretion of dietary porphyrins
Where do spinal fractures/subluxations commonly occur in rabbits?
L7
Adenovirus infection of rabbits has been observed in what organ system?
Gastrointestinal, spleen, kidney and respiratory (lung) tract systems (systemic disease)
What is the natural host for rabbit (Shope) papilloma virus?
Cottontail rabbits (Sylvilagus)
How is rabbit (Shope) papilloma virus spread?
Mechanical (insects)
What lesions are seen in infected domestic rabbits?
Papillomas of the ears and eyes that tend to regress after several weeks.
Virally induced papillomas in domestic rabbits shed virus. T or F?
False; virus is not produced in lesions observed in Oryctolagus; however, virus is produced in Sylvilagus, the natural host.
What is a potential of papilloma virus stocks obtained from Sylvilagus? What pathogenic effects are observed?
Papovavirus (a polyoma virus); none, not even in inoculated domestic rabbits.
What lesions are seen with rabbit parvovirus? Are high antibody titers common? Is clinical disease common?
Enteritis has been described; many colonies of rabbits in North America have high antibody titers; disease is not common.
Rabbit (Shope) fibromatosis lesions are more severed in domestic rabbits (Oryctolagus) than in cottontails (Sylvilagus). T or F?
False; both genera of rabbits are affected (unlike rabbit (Shope) papillomatosis)
In natural rabbit pox infections, where is the primary site for viral replication?
Respiratory tract
In rabbits with Shope papillomatosis, where do lesions usually occur?
Eyelids and ears
What virus is the only member of the family Papovaviridae for which the domestic rabbit is the natural host?
Rabbit oral papillomavirus
Leproid herpesvirus 1 has been isolated from domestic rabbits. T or F?
False; virus isolated from cottontails, and although is infective for prepared kidney cells from domestic rabbits, attempts to infect NZW rabbits have been unsuccessful
Domestic rabbits can be naturally and experimentally infected with herpes simplex 1 virus. T or F?
True; used as a model for herpes simplex encephalitis
What are several synonyms for Rabbit Hemorrhagic Disease (RHD)?
This virus is closely related to what other calicivirus infection of rabbits?
European Brown Hare Syndrome
What is the underlying pathology of lesions seen with RHD?
Disseminated intravascular coagulation
How is the virus transmitted (acquired)?
Oral ingestion
What is the organ of choice to detect viral antigen or to visualize viral particles by EM?
Liver
How is rabbit coronaviral enteritis diagnosed?
EM detection and identification of viral particles (has not been cultured in vitro yet)
Coronaviral particles have been detected in the feces of normal rabbits. T or F?
True; its role as a primary pathogen is not known
What other disease syndrome has been associated with coronavirus infection in rabbits?
Pleural effusion disease and cardiomyopathy
What is a likely source of this (these) strain(s) of virus?
Humans (virus shown to be antigenically related to human coronavirus strains)
Experimental infection with what unrelated organism was associated with coronavirus infection in rabbits?
Treponema pallidum
What type of diarrhea is associated with rotavirus infection in rabbits? Why? What age rabbits are most likely affected?
Osmotic diarrhea due to damage of enterocytes that synthesize disaccharidases. These sugars remain in the lumen of the gut, causing an osmotic drain of fluids from the tissues. Usually affects young rabbits still nursing. Brush border enzymes change as diet goes from milk to plant material.
What disease(s) is(are) frequently superimposed on rotaviral infection in rabbits?
Bacterial enteritis (E. coli); coccidiosis
Sendai virus infection in rabbits results in a severe, descending, necrotizing rhinitis and bronchitis. T or F?
False; there is evidence that it infects, replicates in and is shed from the upper respiratory tract, but clinical disease is not seen.
What are three differential diagnoses for young rabbits that are thin, dehydrated, and have distended watery fecal material within their cecum?
E. coli infection, coronaviral infection, rotaviral infection, coccidiosis
Viral Hemorrhagic Disease of rabbits has a high morbidity (up to 80%), but rarely causes death. T or F?
False (mortality up to 90%)
In Viral Hemorrhagic Disease of rabbits, what systemic pathology is thought to play a significant role in the pathogenesis of the disease?
Disseminated Intravascular Coagulation
In kits born to infected rabbits, what is the usual time/age for establishment of pasteurellosis?
3 months of age
Aerosols do not appear to play a major role in spread of pasteurellosis in rabbit facilities with adequate air exchange. T or F?
True; direct contact (nasal or genital) appears to be mode of transmission
Name two examination procedures that should always be performed during rabbit necropsies that may not be routinely performed on necropsies of other species and why these are performed.
1. Removal of nasal bones overlying turbinates and examine for turbinate atrophy or exudate associated with chronic rhinitis/pasteurellosis
2. Open the tympanic bullae and examine for suppurative otitis media that may be associated with subclinical pasteurellosis
Fibrinous pleuritis or serositis is rarely present in rabbits with clinical pasteurellosis. T or F?
False � pleuritis occurs with lower respiratory tract form and serositis in does with reproductive form.
What Pasteurella serotypes are associated with upper respiratory tract disease? With lower respiratory tract disease?
Rhinitis usually due to 12A
3A and 3D more common with pneumonia
Bordetella bronchiseptica is a bonafide respiratory pathogen of rabbits. T or F?
False; many rabbits have titers to B. bronchiseptica without clinical evidence of disease. More likely a co-pathogen
What are three lesions in the lung in rabbits infected with Bordetella bronchiseptica?
1. Suppurative bronchopneumonia
2. Interstitial pneumonia
3. Peribronchial lymphocytic cuffing
In what age rabbits should Bordetella bronchiseptica be considered a potential pathogen?
4-12 weeks of age
Name two bacteria that have been shown to localize along the cilia of respiratory epithelial cells in rabbits.
Bordetella bronchiseptica
CAR bacillus
CAR bacillus is considered a pathogen in laboratory rabbits. T or F?
False; serology indicates that CAR bacillus is common in rabbitries, but animals are usually asymptomatic
What is the usual etiologic agent of pododermatitis (sore hocks) in rabbits? What contributes to this disease?
Which of the following are true regarding rabbit syphilis:
A. The etiology is Treponema cuniculi.
D. Intrauterine transmission does not occur.
E. The method of choice for diagnosing rabbit syphilis is examination of wet mounts under dark field microscopy.
What is the currently accepted nomenclature for T. cuniculi?
Treponema paraluiscuniculi
What serologic test is available to diagnose rabbit syphilis?
Wasserman antibody test
What are the common macroscopic changes in pregnant does found dead due to listeriosis?
Straw-colored fluid present in the peritoneal cavity. Disseminated, pale, miliary foci of necrosis in the liver, edema of regional lymph nodes, splenomegaly, and visceral congestion.
Serologic diagnosis is the method of choice for confirming listeriosis is rabbit abortion cases. T or F?
False; recovery of the organism is best for confirming diagnosis.
How is Tyzzer�s disease acquired in rabbits?
Fecal-oral route
How does Clostridium piliforme disseminate to the liver in rabbits?
Via portal circulation after replication in the intestinal mucosa
What are the macroscopic lesions commonly seen with Tyzzer�s disease after opening the abdominal cavity?
Ecchymoses and fibrinous exudate of serosa of cecum and colon. Pale miliary foci in the liver.
Name three anatomic locations in rabbits that microscopic lesions due to Tyzzer�s disease are present. List in order of lesion prevalence.
Intestinal tract > liver > myocardium
In Tyzzer�s disease, intracytoplasmic bundles of bacilli present in hepatocytes at the periphery of focal lesions. T or F?
True
Name two other infectious agents that should also be ruled out to eliminate the possibility of concurrent infections in rabbits with Tyzzer�s disease.
E. coli, coccidiosis
What are the typical histologic findings in the ileum of rabbits with coliform enteritis?
Villi are blunted, lamina propria is edematous and contains predominantly heterophils. Villus tip epithelial cells are swollen and bacterial colonies are attached to the brush border.
Coliform enteritis is usually categorized as what type of E. coli strain?
Enteropathogenic E. coli. They do not appear to produce enterotoxins, and do not appear to be enterinvasive.
E. coli is a normal inhabitant of the rabbit intestinal tract. T or F?
False
In general, E. coli isolates are age-specific in rabbits. T or F?
True; isolates from sucklings are not infective for weanlings, and vice versa.
What is the etiologic agent of rabbit proliferative enteritis/histiocytic enteritis?
The agent of rabbit proliferative enteritis/histiocytic enteritis is species-specific. T or F?
False; there appears to be little genetic variation among organisms from one host species to another.
What is a histopathologic, diagnostic feature of rabbit proliferative enteritis/histiocytic enteritis?
Organisms in the apical cytoplasm of enterocytes.
What is a frequent co-pathogen in this enteritis disease?
E. coli
What is the pathogenesis of clostridial enterotoxemia in rabbits?
Rabbits ingest high energy feed> failure to degrade and digest the carbohydrates in the small intestine> carbohydrate overload reaches large intestine and promotes overgrowth of organisms such as clostridia> disturbances in osmolality, production of enterotoxins, diarrhea and death.
What is the most common clostridial pathogen associated with enteritis complex in juvenile rabbits? What other clostridial pathogens have been identified in rabbits?
spiroforme
C. difficile, C. perfringens, C. piliforme
What toxin has been implicated in cases of fatal clostridial enteropathies?
Type E iota toxin
What lesions are suggestive of clostridial enteropathy?
Selective necrosis of mucosal epithelium with sparing of crypts and lamina propria (typical of a luminal toxin); submucosal edema, mucosal/submucosal/serosal hemorrhage
Describe the cecal microflora in rabbits with mucoid enteropathy.
Marked rise in coliform bacteria
In mucoid enteropathy (ME), the cecum contains large quantities of clear gelatinous mucus. T or F?
What is a frequent finding on physical exam of rabbits with ME?
Succussion splash
The acute septicemic form of Staphylococcus aureus infection occurs in what age rabbits? What are common clinical signs?
Suckling kits less than one week of age; multifocal suppurative lesions of viscera
What is the etiologic agent of �Schmorl�s disease�? What disease does it cause?
Fusobacterium necrophorum; moist dermatitis (especially of the dewlaps)
Name two dermatophytes that cause ringworm in rabbits.
Trichophyton mentagrophytes, and Microsporum canis
What two intestinal coccidia are considered the most pathogenic in rabbits?
Eimeria flavescens and Eimeria intestinalis
How is intestinal coccidiosis in rabbits best controlled? Why?
Rigid sanitation practices. Oocysts require one or more days to sporulate at room temperature in order to be infective. Because of this, ingestion of night feces does not appear to play a role in transmission, either.
What condition is often concurrently seen in rabbits with intestinal coccidiosis?
Coliform enteritis (marked rise in E. coli counts)
In rabbits with intestinal coccidiosis, where do microscopic lesions generally occur?
Caudal half of small intestine and in the cecum
Describe the gross lesions seen in rabbits with hepatic coccidiosis. What is the etiologic agent of hepatic coccidiosis?
Multifocal raised, yellow to pearl gray caseous foci; Eimeria stiedae
Cottontail rabbits are an important reservoir host of Encephalitozoon cuniculi. T or F?
False, false wild (Sylvilagus) rabbits have not been found to be seropositive.
How can E. cuniculi be distinguished from Toxoplasma gondii infection histologically?
E. cuniculi = Gram positive
T. gondii = Gram nothing
Since seroconversion precedes renal shedding, rabbits infected with Encephalitozoon cuniculi can be identified before they are excreting organisms. T or F?
True; takes a while for the critters to find the kidneys (and brain)
Name two common lesions in dwarf rabbits attributable to encephalitozoonosis.
Meningoencephalitis (can be seen in other breeds, too) and ocular disease (cataractous change, uveitis)
What is the scientific name of the rabbit pinworm?
Passalurus ambiguus
What is the best means to identify Baylisascaris infection in rabbits?
Postmortem (histopathology and/or Baermann flotation of CNS tissue)
What animal is the natural host for Baylisascaris? How are rabbits infected?
Raccoon; ingestion of infected feces
Rabbits are the intermediate host for which dog tapeworm? What lesions are seen at necropsy?
Taenia pisiformis; focal to linear hepatic lesions
What is the scientific name of the rabbit ear mite?
Psoroptes cuniculi
Name two fur mites found on rabbits.
Cheyletiella parasitovorax
Listrophorus gibbus
Where do vertebral fractures most commonly occur in rabbits?
L7
What environmental/management factors contribute to barbering in rabbits?
Low roughage diet; boredom
Like cats and dogs, rabbits have a third eyelid. T or F?
True
What is the characteristic change in the liver in rabbits with gastric trichobezoars?
Hepatic lipidosis
What is the characteristic histopathologic finding in rabbits with intestinal plasmacytosis? What age rabbits are usually affected?
Marked infiltration of lamina propria of small intestine and cecum with well-differentiated plasma cells; mature rabbits (thought to be immune mediated).
What is the histopathologic lesion associated with vitamin E deficiency in rabbits?
Myocardial interstitial fibrosis, mineralization and myofiber degeneration
Lesions associated with vitamin A deficiency and oversupplementation are distinctly different. T or F?
False; poor fertility, congenital anomalies (microencephaly, hydroencephaly, cleft palate), weak thin kits are seen with both conditions
What lesions are seen at necropsy in does suffering from pregnancy toxemia?
Marked fatty infiltration of liver and adrenal glands.
Congenital buphthalmia occurs most frequently in what breed rabbit? What is the primary defect? Describe the genetics of this disorder.
NZW; primary defect is incomplete cleavage of iridocorneal angle, resulting in impaired drainage of aqueous humor from anterior chamber, and increased intraocular pressure. This is inherited as an autosomal recessive trait with incomplete penetrance (some homozygous recessives may not develop clinical disease)
Uterine adenocarcinomas are the most common neoplasm of aged (female) rabbits. T or F? What must these be differentiated from?
True; endometrial venous aneurysms
What neoplasm has been associated with mammary gland enlargement in aged, primiparous NZW does? What does this neoplasm secrete?
Pituitary adenoma; most of these secrete prolactin
What is the most common neoplasm in juveniles and young adult rabbits? Has a viral agent been associated with this neoplasia?
Lymphosarcoma; no, does not appear to be virally mediated in rabbits.
