Rabbit Medicine, Pt. 2 Flashcards
What is normal to seen in the GIT of rabbits on radiographs?
- food within stomach and lower GI
- gas dispersed throughout
Normal abdominal radiograph, rabbit:
What is the normal anatomy of the rabbit liver? What makes up a majority of its mass?
2 major lobes –> left and right both subdivided into lateral and medial lobes with quadrate and caudate lobes on the right (caudate prone to torsion
gut-associated lymphoid tissue (spleen is small)
What is always an abnormal finding when auscultating rabbit hearts? What can mimick a murmur?
arrhythmias
respirations
What are some causes of increased and decreased lung sounds in rabbits?
INCREASED - edema, pneumonia
DECREASED - pulmonary consolidation, intrathoracic fluid or mass
How do rabbits breath? What is a normal finding on bronchial endoscopy? What is normal finding on BAL cytology/microbiology?
obligate nasal breathers –> mouth breathing is a poor prognostic sign
severe hyperemia
higher amounts of macrophages
What are 3 normal parts of the normal anatomy of rabbit lungs?
- 3 left lung lobes - cranial, middle, caudal
- 4 right lung lobes - cranial, middle, caudal, accessory
- no connective tissue septa - pneumonia is ALWAYS lobar
What is the soft palate of rabbits like? What is their normal respiratory rate?
long, overlies epiglotting –> flips up when neck is hyperextended
30-60 bpm –> >200 with stress or hyperthemia
What is indicative of severe respiratory compromise in rabbits? What is a less significant finding?
open-mouthed breathing + nostril flaring
diaphragmatic breathing - thoracic wall excursions normal
What are common abnormalities seen in the upper respiratory system of rabbits?
nasal d/c or swelling - infection, neoplasia, FB (hay)
dermatitis - treponemiasis (rabbit syphilis, check perineum)
How is the CVS of rabbits evaluated? What are some normal findings?
doppler-echo
- relatively small heart
- left cranial vena cava and coronary veins terminate in coronary sinus
- limited collateral coronary circulation
- right AV valve has 2 cusps
- arthersclerosis
What are 4 normal findings on abdominal examination of rabbits?
- unable to vomit
- stomach and cecum contain soft, compressible ingesta and minimal gas
- borborygmus auscultable
- fecal pellets palpable in colon
What are some abnormal findings on abdominal examination of rabbits?
- difficult to palpate organs (obesity)
- dry, doughy ingesta (ileus, cecal impaction)
- tympany (obstruction)
- hypermobility, diarrhea (enteritis)
- painful cranial palpation (liver lobe torsion)
- uterine pathology
- thick compressible bladder (calcium sludge)
What are some abdnormal soft tissue/integumentary findings in rabbits?
- focal alopecia and superficial crusting - mites, sebaceous adenitis
- swellings/masses - abscesses, neoplasia, Cuterebra larvae
- wounds
- maggot infestation
What is commonly secondary to uterine disease in rabbits?
mammary gland hyperplasia and milk production
(primary neoplasia, like adenocarcinoma, not as common as in uterus)
What is found adjacent to genitalia in rabbits? What are some rectal/perineal abnormalities?
paired scent glands
- urine scald
- papillomatous rectal polyps
- fecal or cecotroph matting
- maggots
What is normal kidney structure in rabbits? What are 2 unique aspects to their urine?
unipapillate - 1 papilla, 1 calyx enter ureter
- fractional excretion of calcium is 45-60% - prolonged high Ca intake can result in aortic and renal mineralization
- biological or plant pigments excreted normally in urine - give a yellow to red color
What is the normal color or rabbit urine? What are 2 abnormal findings?
cloudy orange or reddish due to porphyrin (heme breakdown), will be homogenous
- blood - heterogenous clots or streaking
- calciuria - sludge
What is the normal anatomy of the rabbit uterus? What kind of ovulators are they? What is fetal resorption related to?
lacks a uterine body, has 2 uterine horns and 2 services
induced ovulators
dominance - common in subordinate does
What is normal gestation and litter size in rabbits? What is weaning like?
30-33 days - does pull fur to make nest a few days before parturition
4-24 altricial kits
does nurse kits once or twice daily and they begin to wean at 4-6 weeks
What should be done prior to OVH surgery in rabbits? What are 2 options for performing this surgery?
empty bladder to avoid contamination of peritoneal cavity
- ligate each uterine horn separately if removing cranial to cervix
- ligate at dorsal vagina if removing caudal to services
What are 2 normal findings when performing an OVH in rabbits?
- small ovaries
- mesometrium is highly vascular and primary site of fat storage
When do male rabbits go through puberty? When do their testicles descend?
6-10 months
3 months –> inguinal rings remain open, which allows testicles to retract into abdomen with fear, stress, or cold temperatures
(testicular lesions not common, usually neuter for behavioral reasons, like urine marking)
What kind of castration is required for male rabbits? How is the surgery site closed?
closed castration –> open inguinal rings
bury sutures in SQ and used tissue glue on skin
What is a common neurological finding in rabbits? What are some signs?
vestibulitis
- nystagmus
- head tilt
- rolling (evaluate cornea)
What is the preferred site of blood collection in rabbits? What are 4 other options? How should systems be set up?
lateral saphenous - sternal or lateral recumbency, more proximal
- marginal ear veins - hold off a long time, hematoma common
- ventral ear artery (suboptimal)
- jugular vein
- cephalic vein
blood clots readily - flush with heparin and use a butterfly catheter
What are 2 options for urine collection in rabbits?
- manual expression
- cystocentesis - avoids iatrogenic rupture
Where are IM injections given in rabbits?
lumbar musculature (epaxials) and quadriceps
What is a normal finding in blood smears of rabbits? What is the normal lifespan of RBCs?
marked anisocytosis, higher reticulocyte numbers in younger rabbits
60-70 days
What are the 3 most common leukocytes seen in rabbit samples?
- heterophils (no neutrophils!)
- lymphocytes in younger rabbits
- pseudoeosinophils - small granules
(heterophils and lymphocytes equal >13 months)
What is the primary infection-fighting WBC in rabbits? What is most commonly seen with infections?
heterophils - does not contain lysozymes to liquefy purulent material
leukocytosis rare - heterophils > lymphocytes (also seen with stress due to cortisol release)
What are platelet counts in rabbits like?
higher compared to dogs and cats
- > 800000 can indicate reactive thrombocytosis in response to inflammation or hemorrhage
Why is total protein counts for rabbits not commonly accurate in rabbits? ALT? What kidney values are evaluated?
analyzers use dye-binding assays with bromocresol green (BCG), which has poor affinity for rabbit serum proteins –> should use serum electrophoresis or assays validated for rabbit blood
not liver-specific –> associated
BUN, creatinine
What is best to submit for abscess cultures in rabbits?
wall > contents
submit for both aerobic and anaerobic cultures
What vein is avoided for injections?
ear veins –> thrombosis common
(use cephalic or saphenous)
What are some options for placing IV catheters in rabbits?
cephalic, saphenous, or mammary veins with 22-24 g catheter
- weigh benefits with cost of stress
What bone is used for IO catheters in rabbits? What equipment is used?
proximal femur greater trochanter
- 20-22 g spinal needle (1-1.5 in)
- anesthetize unless patient is critical
What kind of medications must be used for oral administration?
- commercially available or compounded liquids via dosing syringe through diastema
- crush tablets in veggie baby food, mashed banana, or flavored enteral drink
CANNOT PILL
What is the daily fluid requirements for rabbits? How is it given IV/IO? SQ?
100-120 mL/kg
fluid pump or small-volume infusion set
in 8 hour intervals
How should rabbits be housed in hospitals?
- same cages as for cats and dogs, but housed away from predator species*
- quiet wards
- litter box without kitty litter
- allow a hide area
- water bottle or bowl
Why is it not recommened to place E-collars on rabbits?
will likely not eat well and will be unable to eat cecotrophs
(maximize fiber with feedings)
What are some indications for parenteral feeding in rabbits? What is important to note about this method of feeding?
- oral or GI lesions preclude enteral feeding
- anorexic rabbit resisting syringe feeding
does not feed enterocytes or stimulate motility –> dextrose, lipids, amino acids
What is a good option for sedation in rabbits?
quiet, calm environment + Midazolam +/- opioid
How should rabbits be fasted before surgery? What induction is used?
fast for several hours - cannot vomit, but ensures the stomach is not entirely full
IM butorphanol + Midazolam
What anticholinergic is used in rabbits?
glycopyrrolate –> rabbits produce atropinase
What IV fluid rate is used in rabbits during surgery? How are they monitored?
10 mL/kg/hr
- pulse ox
- doppler
- water-circulating heating pad, convective heater
Why should rabbits be carefully shaved? What scrub is preferred?
thin skin
chlorhexidine scrub - less irritating than povidone-iodine
What are some post-op needs for rabbits?
- quiet, calm environment
- analgesia - Buprenorphine, Butorphanol, Oxymorphone, Meloxicam
- thermoregulation - incubator
- nutritional support
Are there vaccines approved for use in rabbits in the US? When are females recommended to be spayed?
no –> Europe and Australia have annual vaccines for Myxomatosis and Calicivirus (rabbit hemorrhagic disease)
before 2 y/o to prevent uterine neoplasia
What are 3 common GI diseases seen in rabbits? What are signs of each? What causes each?
- enteritis complex - soft stool, diarrhea, enterotoxemia, death - stress, diet, antibiotics
- enterotoxemia - commonly seen in 3-6 weeks old - Clostridium spiroforme
- mucoid enteritis - commonly seen in 7-14 weeks old, anorexia, lethargy, weight loss, diarrhea, impaction - unknown, bacterial dysbiosis, hyperacidity of cecum
What are 7 antibiotics that can lead to dysbiosis in rabbits? What drugs are preferred?
- Clindamycin
- Lincomycin
- Ampicillin
- Amoxicillin (+/- clavulanic acid)
- Cephalosporins
- oral penicillins
- Erythromycin
Fluoroquinolones, Sulfas, Chloramphenicol, Azithromycin, Metronidazole, injectable Penicillin
What 3 treatments are recommended for enteritis in rabbits?
- aggressive supportive care
- Chloestyramine - binds bacterial toins associated with Clindamycin-induced
- Metronidazole
What are 4 options for preventing enteritis in rabbits?
- high fiber diet
- avoid sudden diet changes
- make hay available to weanling rabbits (3 weeks)
- avoid early/forced weaning
What are the 3 main causes bacterial enteritis in rabbits? Some additional?
- enteropathologenic E. coli - treated with TMS or Enrofloxacin until C/S results are obtained
- Lawsonia intracellularis - proliferative enteritis, acute diarrhea for 2-4 months
- Clostridium piliforme - Tyzzer’s disease, watery diarrhea in weanlings
Salmonella, Pseudomonas
What are the 3 most common causes of viral GI disease in rabbits?
- Papillomatosis - oral growths in lab rabbits
- Coronavirus - diarrhea in lab rabbits, common in 3-10 weeks
- Rotavirus - high morbidity/variable mortality, villous atrophy at ileum
How does rabbit hemorrhagic disease virus cause death? Where has this disease been seen?
causes hepatic necrosis and death from DIC in >2 months old rabbits
- domestic rabbits, wild cottontails, jackrabbits, hares (US RHDV2)
- endemic in Europe, Cuba, Australia, NZ
- outbreaks in Middle East, South America, US
How can the RHDV vaccine be obtained?
coordinate through state vet and USDA, only allowed in states where cases have been reported
- commonly delayed and cost prohibited for shelters
- Eravac, Filavac, US development through Medgene Labs
- onset of immunity 1 week post vax with annual booster
What is the most common parasite seen in rabbits? What are 2 types?
coccidia
- HEPATIC - E. stiedae, decreased hepatic function, bile duct obstruction
- INTESTINAL - E. perforans, subclinical common, signs associated with poor husbandry and overcrowding
What are 3 other common parasites seen in rabbits? What are some non-pathogenic ones found?
- Cryptosporidia - C. parvum, diarrhea in young rabbits, peaking at 30-40 days
- nematodes - Passalurus ambiguus (pinworm)
- cestodes - Cittotaenia variabilis
- Giardia duodenalis
- Entamoeba cuniculi
- Monoceroceomas cuniculi
- Retortamonas cunicili
What are the 4 most common cause of respiratory disease in rabbits?
- Pasteurella multocida - rhinitis, sinusitis, conjunctivitis, nasolacrimal infection, otitis, tracheaitis, pneumonia, abscesses
- Bordetella bronchiseptica - common inhabitant, prevalence increases with age
- Psuedomonas spp
- Staphylococcus spp
What has been isolated in rabbits with respiratory signs housed close to rats?
Mycoplasma pulmonis
What is a common cause of viral respiratory disease in rabbits? What is the most common etiology of fungal granulomas?
Myxoma virus –> nasal and ocular disease
injury
What is the most common cause of neoplasia in female rabbits? What is the first sign? When is treatment recommended?
uterine adenocarcinoma - hematogenous metastasis within 1-2 years
hematuria or serosanguinous d/c
OVH if there are no signs of metastasis
What can mimic uterine adenocarcinoma in rabbits?
endometrial hyperplasia or uterine polyps
What are the 2 most common isolates from pyometra and endometritis in rabbits?
- P. multocida
- S. aureus
In what 3 situations is pregnancy toxemia seen in rabbits? What are some signs?
- last week of gestation (nest building)
- obese rabbits
- inadequate caloric intake
- weakness, depression
- incoordination
- coma
- abortion
What treatment is recommended for pregnancy toxemia? How can it be avoided?
- supportive care
- fluids + calcium
- analgesia
avoid underfeeding and obesity during pregnancy and provide alfalfa
What is indicative of pseudopregnancy in rabbits? What causes it?
hair pulling
corpus luteum secretes progesterone –> commonly resolved spontaneously, may involve hydrometra or pyometra
What is a common cause of subclinical interstitial nephritis? What are common isolates of pyelonephritis?
Encephalitozoon cuniculi
P. multocida, Staphylococcus spp
What are some noninfectious causes of renal disease in rabbits?
- hypercalcemia
- renal calcinosis
- hypervitaminosis D
- fatty degeneration from obesity
- lymphosarcoma
What are some medical causes of nephrotoxicity in rabbits? When does urinary bladder eversion commonly occur?
- Gentamicin
- Telazol (tiletamine)
- Diclofenac
after kindling
What are common isolated from abscesses in rabbits? How are they treated?
- Staph
- P. multocida
- Pseudomonas
- Proteus
- Fusobacteria
- Bacterioides
- Actinomyces
surgical excision, antibiotics, PMMA beads –> common at tooth roots and retrobulbar
What is moist dermatitis commonly secondary to? What are signs?
dental disease
- wet dewlap
- urine scald
What causes ulcerative pododermatitis in rabbits?
clipping of hair on feet –> lack paw pads
What are 2 causes of dermatophytosis in rabbits?
- Trichophyton mentagrophytes*
- Microsporum spp
What are 4 common ectoparasites that affect rabbits? What treatment is avoided?
- Psoroptes cuniculi - ear mite
- Cheyletiella parasitovorax - fur mite (zoonotic)
- Leopracarus gibbus - fur mite (not zoonotic)
- Ctenocephalides felis/canis - fleas
Fipronil (Frontline) - GI signs, seizures –> can use Selamectin
What are the most common causes of myiasis in rabbits?
Cuterebra and Wohlfahrtia vigil - maggots of dipterid flies
What is the most common tick found in rabbits?
Haemaphysalis leporis-palustris
(continental rabbit tick)
What dermatologic virus is commonly seen in rabbits? How is it transmitted? What acts as a reservoir? What signs are associated?
Myxomatosis (pox family)
arthropod bites
wild rabbits (Sylvilagus)
- skin tumors in wild rabbits
- lethargy, anorexia
- fever
- skin hemorrhage
- high mortality
What is the natural host of rabbit (shope) fibroma virus? How is it transmitted? What signs are seen?
Easter cottontail (Sylvilagus floridanus)
biting arthropods
wart-like tumors on face, feet, legs, and perineum
What transmits rabbit (shope) papilloma virus? What signs are seen? How does it typically progress?
biting arthropods
keratinized lesions on ears, eyelids, neck, and shoulders
SCC (may spontaneously resolve)
What causes Encephalitozoonosis? What are some signs? How is it diagnosed?
Encephalitozoon cuniculi - fungi
- behavioral changes
- head tilt
- nystagmus
- ataxia, rolling, seizures
- renal pathology
- phacouveitis
- pneumonitis
indirect immunofluorescence, ELISA
What does a positive result for Encephalitozoonosis indicate?
exposure, not cause of disease
repeat titers 3-4 weeks later + urine antibody analysis, CSF
What treatment is recommended for Encephalitozoonosis? What are some side effects?
Benzimidazoles –> Oxibendazole, Fenbendazole, Albendazole
bone marrow suppression, death
What are 6 common causes of neurologic disease in rabbits?
- cerebral larval migrans - Baylisascaris spp causes tremors, ataxia, circling, and vertical nystagmus (Oxibendazole)
- aberrant Cuterebra migrans
- Toxoplasmosis - uncommon, granulomatous meningoencephalitis
- otitis interna
- rabies
- herpes simplex virus
What are signs of arthritis/DJD in rabbits? What is seen in radiographs?
- abnormal gait
- lameness
- inability to hop
- quiet, old, unkempt/messy
spondylosis, narrowed joint spaces, scoliosis
What treatment is recommended for arthritis/DJD in rabbits? How should their enclosure be altered?
pain management - NSAIDs, Tramadol, Chondroitin, Glucosamine, Myristol, acupuncture, omega 3-FA
lower litterbox edge, proper hygiene
What are some causes of vision loss in rabbits? What changes should be made when this occurs?
- lenticular sclerosis
- cataracts
- glaucoma
keep a consistent schedule with food and water and cage changes, speak when approaching, provide a companion
