Tufts OpenCourseware
Authors: Joerg Mayer, D.V.M., Gretchen Kaufman, DVM
Color Key
Important key words or phrases.
Important concepts or main ideas.

OCW Zoological Medicine 2008
Rabbit Medicine (2009)
J. Mayer, DVM / G. Kaufman, DVM
Cummings School of Veterinary Medicine at Tufts University

1. Learning Objectives and Review

1.1. Learning Objectives

This section on Rabbit Medicine will give you a good review of the major husbandry challenges, diseases, and clinical approaches to rabbit health issues. Color coded topics indicate learning objectives that the student should become familiar with. Cases will be presented in class to illustrate these topics. At a minimum, you will be expected to be familiar with the following:

  • Be familiar with the clinically relevant anatomy and physiology of the domestic rabbit, especially teeth and GI tract.

  • Be able to interpret a rabbit hemogram

  • Understand the complications association with obesity in the pet rabbit

  • Understand why it is recommended to spay female rabbits early in life.

Be familiar with the various disease syndromes associated with Pasteurella multocida and how they are treated in the domestic rabbit

  • Know how to diagnose and manage a hairball in a domestic rabbit

  • Be familiar with the various disease syndromes associated with hypercalcemia in the rabbit

  • Understand the management of dental malocclusion in the rabbit

  • Know the importance of closing the inguinal ring in surgical castration of the male rabbit

  • Know the antibiotics that are safe to use in the domestic rabbit and why this is an important issue

  • Be familiar with the zoonotic diseases associated with rabbits

1.2. Review and Resources on Rabbit Medicine

Please review relevant material from 1st year Comparative Anatomy course before attending these lectures. Additional material can be found in

  • A Colour Atlas of the Anatomy of Small Laboratory Animals: Rabbit Guinea Pig by Peter Popesko, et al.

The ICE First Step Program on Exotic Small Mammal Medicine, developed by Theresa Lightfoot, is a great supplement to this.

Information on laboratory animal medicine will be discussed in an upcoming lecture and can also be obtained from the references below.

References and Resources

Conservation Medicine Challenges

Supplemental Readings


2. Rabbit Taxonomy

Order Lagomorpha

Family Ochotonidae – pikas

Family Leporidae - rabbits and hares

Genus Lepus

Genus Sylvilagus

Species europaeus - European hare

Species arcticus - Arctic hare

Species americanus - Snowshoe hare

Species transitionalis - New England cottontail

Species floridanus - Eastern cottontail

Genus Oryctolagus

Genus Brachylaugus

Species cuniculus - European rabbit

Species idahoensis - Pygmy rabbit

Most of the following discussion will concern the european rabbit or Oryctolagus cuniculi. The common pet rabbit and the New Zealand white laboratory rabbit belong to this species. Rabbits were domesticated beginning in Roman times and extending into the 16th century for use as a source of food and for sport hunting. There have since been the development of many breeds within this species that constitute the great variety we see as pet and laboratory animals. Some common breeds are: English and French Angora, Belgian Hare, Californian rabbit, American Dutch (4.5 lbs.), Dwarf (2 lbs.), Flemish Giant (15 lbs.), French and English Lops, Mini Lops (6 lbs.), New Zealand White, Rex, Satin, Silver Martin.(see photos and more at ARBA breed site )


3. Basic physiologic and anatomic parameters

Life span

Up to 12 years

Body temperature

100-104º F

Heart rate

200-300 bpm

Respiratory rate

32-60 bpm

Sexual maturity

12-24 weeks (breed variability)

Rabbit respiratory rate, heart rate and body temperature are prone to increase when stressed (i.e. in the exam room after sitting in a waiting room full of dogs). Temperatures of 104 are not unusual in such situations and should not be mistaken for pyrexia. Frightened or stressed rabbits may also inhibit their palpebral reflex, making visual assessment difficult. They usually have no menace reflex.

Rabbit urine is cloudy and thick, similar to a horse. It normally contains calcium carbonate crystals. Excessive crystals can occur and lead to stone formation. Rabbit urine also may contain porphyrins (orange to reddish in color) which must be differentiated from blood.

Rabbit dentition

  • Incisors 2/1

  • Canines 0/0

  • Premolars 3/2

  • Molars 3/3

All rabbit teeth are continuously growing open rooted hypsodont teeth. Unlike rodents, rabbits have 4 maxillary incisors. Maloccluded teeth (incisors or molars) will produce abnormal overgrowth and resulting problems. Although malocclusion of any of the teeth is possible, congenital malocclusion of the incisors is most common in rabbits (often due to mandibular brachygnathism).

Rabbits are true herbivores and are considered monogastric hind gut fermenters (similar to a horse).


large distensible stomach (15% of total volume)

can’t vomit

short small intestine (12%)

dog, pig or horse=22%

large intestine


sacculus rotundus

rabbit only

cecum (40%)



1 meter long in NZW

3.1. Reproduction

Please review Reproductive physiology notes.

  • Rabbits are induced ovulators.

  • Rarely are there external signs of receptivity (swollen vulva, behavioral changes). Vaginal cytology can be used to determine optimal receptivity. Females remain receptive during pregnancy until the last trimester and during lactation.

  • There is a slight seasonal suppression of breeding activity in the fall in domestic rabbits. Wild rabbits are seasonal breeders.

  • Ovulation can be artificially induced with luteinizing hormone or human chorionic gonadotropin.

  • Pseudopregnancies are not uncommon and may last 15 - 17 days.

  • Artificial insemination is possible in rabbits.

  • Pregnancy lasts 29 - 35 days depending on the breed of rabbit. The smaller breeds have the shorter gestation periods. Pregnancies can first be palpated from 10-14 days.

  • Litters range from 1 - 22, with the smaller breeds producing the least number of young.

  • Maternal behavior starts with nest building a few days before parturition. Rabbits are very sensitive mothers. Disruption of the nest may result in infanticide.

  • Mother rabbits will only nurse once or twice daily. This event is often missed by unsuspecting owners and babies are sometimes incorrectly removed from the nest for handrearing. Hand rearing is relatively difficult.

3.1.1. Handrearing recommendations Domestic rabbits

  • Recommended feeding schedule for orphan domestic rabbits(daily total quantity given in 3-4 feedings)







1 week



2 week



3 week



4 week



  • At weaning baby bunnies can be offered dry alfalfa/timothy hay mix and pellets at 2-3 weeks, but nursing is recommended until 6 weeks of age to allow adequate intestinal flora to develop, avoiding fatal diarrhea.

  • At 12 weeks small carrot chunks can be offered but leafy greens, fruits and bread should be given only after 16 weeks of age. A bowl of fresh water should always be available.

  • An excellent discussion of hand rearing baby domestic rabbits can be found in the House Rabbit Handbook . Wild rabbits

Eastern cottontail
Eastern cottontail

Raising/feeding wild cottontail rabbits is very different from domestic rabbits.

  • These rabbits develop faster and wean much younger than domestics. They begin to sample solid foods shortly after their eyes open. They wean at 3-4 weeks and can be released once weaned.

  • Their nutrient requirements are different and thus the handfeeding recommendations are different from the above recommendations for domestic bunnies.

  • Some rehabilitators use a mixture of Esbilac and whipping cream, or various other combinations of commercially available products (multi-milk, etc.).

  • Handrearing is very difficult and requires much experience to be successful. It is not recommended for the novice and never should be encouraged in the general public.

4. Special considerations for husbandry and nutrition

4.1. The house rabbit vs. the hutch rabbit

The era of the hutch rabbit is rapidly declining. On the rise is the litter box trained house rabbit, now occupying similar place in the family structure as the house cat. Each type presents a different set of husbandry requirements and problems. The following references are recommended for further reading into these two categories.

  • Hutch Bunny reference: American Rabbit Breeders Association, Inc. PO Box 426 Bloomington, IL 61702 http://www.arba.net/

  • House rabbit reference: The House Rabbit Society 1524 Benton St. Alameda, CA 94501 http://www.rabbit.org/ ; Book: The House Rabbit Handbook by Marinell Harriman

4.1.1. The hutch bunny

The hutch bunny is often a child's pet, school or 4-H project, with little to no involvement of the parent. The rabbit may be housed with others or alone in a pen raised up off the ground and enclosed with wire. The exercise area of the hutch should be large enough for the rabbit to complete 2 hops (6 ft. for NZW) and to stand up fully extended. Many hutch bunnies live all year round in this type of setup. They should have an area in the cage that provides shelter (wooden house) and an area that allows them to get off the wire floor of the cage (wooden platform). The cage should be placed in a protected part of the yard, free from direct sunlight and cold winds. The cage must be predator proof! The sides and top of the cage should be screened to protect from flies.

Problems with this type of husbandry may include:

  • Heat stroke (rabbits are very sensitive to heat)

  • Cold stress with inadequate bedding or shelter

  • Fly strike (Myiasis)

  • Sore hock (Pododermititis)

  • Predator attacks

  • Neglect due to remote location and loss of child's interest

4.1.2. The house rabbit

The house rabbit on the other hand is often a family pet or even an adult pet, usually involving a much stronger rabbit-owner bond than the hutch bunny. These individuals are often loose in the house for part or all of the day, are litter trained, get along with other pets (dogs and cats) and are very well observed.

The most common problems with house rabbits may include:

  • Obesity and hepatic lipidosis

  • Sore hock (hardwood floors)

  • Chronic soft stools

  • Foreign body ingestion (carpeting, plastic)

  • Electric cord chewing

  • Conflicts with other animals

4.2. Nutrition

Please review Feeds and Feeding notes on rabbit nutrition.

It might be assumed that rabbit nutrition is pretty well understood, since they have been used in the laboratory for so long. However, this is apparently not so. There are many problems with pet rabbits which are related to nutrition. It is not as simple as feeding just rabbit pellets anymore. Diets including rabbit pellets alone or rabbit pellets and alfalfa hay have been linked to disorders of excessive calcium, obesity and hepatic lipidosis and chronic soft stools. A diet of pellets alone, without any added roughage will contribute to the development of hairballs. High fiber diets are also thought to be protective against the development of enteritis by helping to maintain normal motility. The lower carbohydrate timothy hay is preferred over alfalfa, since higher carbohydrates favor growth of clostridial species and thus can lead to the development of enterotoxemia.

Ideal rabbit diet includes:

  • Quality high fiber rabbit pellets

  • Timothy hay (free choice)

  • Fresh fruits and vegetables

  • Occasional other grains/treats

Cecotrophy or coprophagy - this is a necessary part of a rabbits daily routine and is required for efficient use of their herbivore diet. Additional vitamins and proteins are obtained through this behavior.


5. Basic diagnostic and therapeutic approaches

Diagnostic testing in rabbits is not particularly special. Physical examination, fecal examination, skin scrapings, etc. are simple and routine. For a sample client history questionnaire see the Appendix.

5.1. Blood sampling

Blood collection in pet rabbits may differ from those techniques used in laboratory settings. Venipuncture is generally performed in the pet rabbit from the marginal ear vein (small samples), the jugular vein, the cephalic vein, or the saphenous vein. Intravenous catheters may also be placed in these locations. Additional sites used in laboratory settings may include the auricular artery, the orbital sinus, and cardiac puncture. These sites are generally not acceptable in pets.

Rabbit blood clots very fast, so it is prudent to fill the EDTA container first when collecting larger volumes. Due to the fact that the lifespan of the RBC is fairly short (57-67 days) a 2-4% polychromasia is a common observation. Nucleated RBC can also be seen in the normal bloodsmear of a healthy rabbit.

5.1.1. WBC and differential

Rabbits differ from most of our familiar domestic small animals in that a leukocytosis with a neutrophilia is rarely observed with bacterial infections. Most often there is only a mild absolute increase in the number of white blood cells, but instead a shift in the distribution of white blood cells is seen. The normal rabbit will usually have slightly more lymphocytes (60%) than neutrophils with a total number of cells around 8-10,000 cells/μl. When challenged with a bacterial infection they will display a shift in the white cells to a neutrophilia and a lymphopenia, often without an overall increase in leukocytes. Stress will also produce a lymphopenia.

Leukogram interpretation is complicated by the commonality of an inverse H:L ratio which occurs secondary to any source of stress (cortisol), including stress from transport or any chronic disease.

Heterophils have the same function as other mammalian neutrophils, but they have acidophilic or eosinophilic granules in their cytoplasm. They are sometimes referred to as "pseudoeosinophils" in the literature.

Normal rabbits tend to have very low monocyte, eosinophil and basophil counts, while a few of the diseased rabbits have elevated counts

Many sick rabbits have haemoglobin and PCV values much lower than normal. This is one of the best ways to quickly check a rabbit for signs of problems.

Red blood cell parameters

White blood cell parameters

PCV (%)

33 - 48

WBC (103/μl)

5 - 12

RBC (106/μl)

4 - 7

Neutrophil (%)

30 - 50

Hb (g/dl)

10 - 15

Lymphocyte (%)

30 - 60

MCV (fl)

59 - 67

Monocyte (%)

2 - 10

MCHC (%)

30 - 35

Eosinophil (%)

0 - 5

MCH (pg)

19 - 23

Basophil (%)

0 - 8

Reticulocytes (%)

2 - 4

Platelets (103/μl)

250 - 600

5.1.2. Serum chemistry

Total serum calcium levels in rabbits often appear high, compared to what is seen with dogs and cats. Levels of up to 16 mg/dl are often seen and are considered normal. However, diseases related to excessive calcium are seen in the rabbit and will be discussed below.

Fat rabbits will often demonstrate elevated triglyceride levels as with other animals with hepatic lipidosis. This is a serious consideration in a rabbit with anorexia caused by conditions such as a hairball, malocclusion, or snuffles. The changes can be seen as rapidly as 24 hours after onset of anorexia!

Chemistry compound

Mean values

Alk. Phos. (U/l)

10 - 70

Amylase (U/l)

200 - 500

ALT (U/l)

25 - 65

AST (U/l)

10 - 98

CPK (U/l)

0.2 - 2.5

LDH (U/l)

33.5 - 129

Total protein (g/dl)

5.4 - 7.5

Albumin (g/dl)

2.7 - 5.0

Globulin (g/dl)

1.5 - 2.7

BUN (mg/dl)

5 - 25

Creatinine (mg/dl)

0.5 - 2.6

Total Bilirubin (mg/dl)

0.2 - 0.5

Glucose (mg/dl)

75 - 140

Cholesterol (mg/dl)

10 - 100

Triglycerides (mg/dl)

50 - 200

Sodium (mEq/l)

138 - 150

Chloride (mEq/l)

92 - 120

Potassium (mEq/l)

3.5 - 7.0

Calcium (mg/dl)

6.0 - 12.5 (14.0)

Phosphorus (mg/dl)

4 - 6

Normal mean values for New Zealand White Rabbits adapted from Manning, PJ. The Biology of the Laboratory Rabbit, 2nd ed., c1994

5.2. Therapeutic options

In general, familiar therapeutic options derived from dogs or cats are likely to be appropriate for related disease syndromes seen in rabbits (heart disease, renal disease, diabetes, etc.). However, due to the rabbit's fragile gastrointestinal flora special care must be taken when selecting antibiotics for the treatment of bacterial diseases. Use of certain antibiotics has been linked to the onset of fatal enterotoxemia (see more below). Drugs to avoid include: lincomycin, clindamycin, erythromycin, and oral β-lactam drugs such as amoxicillin, keflin, etc. Antibiotics which are safe to use include:

  • Enrofloxacin

  • Tetracycline

  • Trimethoprim sulfa

  • Metronidazole

  • Chloramphenicol/Florfenicol

  • Penicillin G given subcutaneously is one of the best treatments to date for resistant respiratory tract and other recurring infections.

Please note that enrofloxacin (Baytril) has been linked with arthropathy in young rabbits and should be used with caution. Please refer to the end of this section for a list of drugs and dosages recommended in rabbits and rodents.

Routes of administration of medications are similar also to small animals. Oral suspensions of antibiotics (e.g. enrofloxacin) or other medications are relatively easy to administer and are especially appropriate for sending home. Suspensions should be made in rabbit friendly flavors. Catheters can be placed in the ear vein or other available sites. Intraosseous catheters can easily be placed in the femur. Rabbits that are not very depressed will chew out IV lines if they have access to them. Intramuscular or subcutaneous injections are also given frequently over the truncal area.

IV catheter
IV catheter

It should be noted that rabbits have a vast and poorly adhered subcutaneous space. If handled roughly, their skin may tear and large degloving injuries may occur. (Such injuries caused by cats are often seen in wild rabbits).

Oral gavage can be achieved with the use of an oral speculum or through a nasogastric tube. Some rabbits are amenable to hand or syringe feeding.

5.3. Anesthesia and surgery

5.3.1. Common problems encountered in rabbit anesthesia

  • unfamiliarity with signs of pain

  • stress during pre op handling

  • inadequate preparation

  • inadequate monitoring and support

  • inadequate follow up

5.3.2. Pain recognition

In prey species the ‘conservation-withdrawal’ reaction is the dominant behavioral pattern over the ‘fight or flight’ reaction of predators. Because of this phenomenon it is important to avoid stress prior to surgery. Prey animals are easily stressed during handling, in an unfamiliar environment, with unfamiliar scents or noises.

Stress + Anesthesia = cardiopulmonary failure.

An adequate preparation for surgery should include:

  • Baseline blood work

  • Fluids pre op

  • NSAIDS pre op

  • Stress free environment

Preemptive analgesia is one of the most important factors of a successful anesthesia regime as it avoids the ‘WIND UP’ of pain sensations. It is also important to provide adequate analgesia pre AND post surgery.

Multimodal analgesia is a combination of different classes (e.g. NSAIDS and Opioids) which will work synergistically and help to reduce the individual doses of drugs and also lower the concentration of the maintenance gas (equals money saved!). Local blocks are often under utilized.

5.3.3. Anesthetic options

Anesthetic options in the rabbit are many, depending on the required degree of restraint and analgesia: from minor restraint or anxiolysis to full and deep surgical anesthesia. A common cocktail uses all 4 drugs given IM in a single injection.

  • Minimal sedation can be achieved with butorphanol or midazolam (diazepam) given IM. Adding ketamine will give additional tranquilization.

    • A great combination is ketamine and midazolam. Deeper sedation can be achieved by adding xylazine.

    • Many practitioners use injectable anesthesia for surgical procedures. The most popular combination is ketamine with xylazine.

  • Telazol (tiletamine/zolazapam) has been shown to be nephrotoxic in the rabbit and should not be used.

  • Propofol may be used for short procedures that do not require surgical anesthesia. A cocktail (ketamine, midazolam, butorphanol) can be given first, or even butorphanol alone, to facilitate the placement of an IV catheter in the marginal ear vein. Propofol is then infused at a steady slow rate to achieve the desired degree of relaxation for the procedure, or for induction, intubation and the addition of gas anesthesia. Apnea can be induced with the use of propofol.

  • Isoflurane is most often used as an inhalant anesthetic. Halothane may also be used.


  • Induction can be performed with the various combinations of drugs discussed above, or with inhalant anesthetics and an induction box or mask.

  • Intubation is somewhat difficult, but is eventually easy to perform with practice on standard sized rabbits. It is performed either by visualization of the glottis using an otoscope/endoscope, or through various "blind" techniques. It is important to realize that iatrogenic trauma from blind intubation can lead to fatal complications. At Tufts we discourage the blind intubation technique due to the fact that we readily have access to good endoscopic equipment.

  • Mask administration throughout the procedure is acceptable if intubation is not possible, but is less desirable

  • Rabbits do not need to be fasted for 12 hours prior to surgery or anesthesia. They should only be fasted for a maximum of 4 hours. Long fasts will result in GI stasis and serious complications following surgery. They should also be encouraged to eat (and thus stimulate their gut motility) as soon as it is safe following anesthetic recovery.

  • Instrumentation for cardiac monitoring and intravenous fluid support are recommended as for dogs and cats and should accompany any major surgical procedure.



10-50 mg/kg IM


2 mg/kg IM


1-5 mg/kg IM


0.2 mg/kg IM


5 mg/kg (induction, see formulary)

5.3.4. Rabbit castration

Rabbit castration is commonly performed for the purposes of contraception and for reducing aggressive or territorial behaviors. It can be performed in a variety of ways as long as care is taken to close the inguinal ring. Rabbits have a very prominent open inguinal ring and are capable of prolapsing into this space following an incorrectly performed castration. The "preferred" technique for rabbit castration is described well, and involves a prescrotal approach as in a dog (Duncan, 1993).

5.3.5. Ovariohysterectomy

Female rabbits are neutered for the same reasons as the male and to prevent the future development of uterine adenocarcinoma. This is very common in the unspayed female domestic rabbit over the age of 4 years (some reports state >90%). It can be seen as early as 2 years. Ovariohysterectomy is therefore recommended before 2 years of age. This procedure is performed as for a cat with one exception. The rabbit has a bicornuate uterus and a double cervix. Separate ligation of each cervix is recommended (Sedgwick, 1982). Obesity complicates the surgery and owners are often asked to get their overweight rabbits to lose weight before the procedure is performed.

5.3.6. Fracture repair

Fracture repair options in the rabbit differ somewhat from the traditional considerations for dogs and cats. External fixation with casts or bandages are usually acceptable if the rabbit will leave the bandage alone. They are prone to chewing at the bandage or self-mutilation of any toes or distal parts of an exposed limb. Internal fixation of difficult fractures of the humerus or femur must be considered, but are not without problems. Rabbits bones are very fragile, brittle and lightweight. The rabbit's skeleton constitutes only 7-8% of their body weight, compared to a cat skeleton which represents 12-13% bodyweight. Long bone fractures will split longitudinally very easily with little manipulation. Great care must be taken by the surgeon to handle the bones gently and to use the minimal implant devices required to repair the fracture. Once stabilized, rabbit fractures heal very quickly.

Amputation is sometimes considered for fractures that are too fragmented, or where the internal fixation attempt results in a shattered bone. Amputation of a forelimb is not a problem. However, amputation of a hindlimb will usually result in severe arthritis/ skeletal deviation in the front quarters of the animal within a year following surgery. This problem must be considered and discussed with the owner before proceeding with a rear limb amputation.

5.3.7. Management of broken back

The rabbit is constructed to be able to deliver a very powerful kick. This is most often used for power and speed in fleeing from a predator. It can also be used to kick a restrainer or to "thump" in the cage as an expression of anger. Under the right conditions a rabbit can kick so strongly that it will result in moderate to severe back injury, from a sprain to an actual displacement or fracture.


An animal presenting with signs of a back injury (hind limb paresis), may not have an associated event or known trauma. Diagnosis should proceed as for a dog or cat, including radiographs and neurologic assessment. Rule-outs should include other causes of neurologic impairment including a spinal cord abscess (often Pasteurella multocida, E.cuniculi).

Treatment may also follow traditional recommendations, however a myelogram and surgical stabilization is rarely considered by the owner. Prognosis for severe injury is grave and euthanasia is often elected. Some cases involving moderate injury (+deep pain) do respond to steroid administration and cage rest.

6. Common problems/diseases

The following lists the most commonly reported problems seen in the domestic rabbit. A brief discussion is included. This list is not exhaustive however. One must always remember that many of the diseases described in dogs and cats ( and humans, horses, or any other mammals for that matter) may occur in any animal, including rabbits. Diagnostic exercises and options for treatment should always leave open these possibilities.

6.1. Understanding the rabbit's response to disease

The domestic rabbit's response to disease is often very unlike that seen in other companion animals. They often do not become febrile, their WBC count may not increase (however there may be a shift in neutrophil to lymphocyte ratio), and the way they handle bacterial abscesses is not like any other animal! A great attempt is made by the rabbit to wall off bacterial infections, as if they are foreign bodies (as they truly are). A great fibrous capsule is produced around the infection site, which usually contains thick caseated pus. This capsule presumably hides the infection from the rest of the animal. This type of abscess will not drain and the capsule may severely limit the penetration of antibiotics to the target site.

Because of this, a well seated infection, especially one involving boney structures, carries with it a guarded to grave prognosis. It is nearly impossible to completely remove (physically) or kill all the bacteria present. The use of antibiotic impregnated beads has shown some promise.

6.2. Viral diseases

Viral diseases have not been a major problem in pet rabbits in the U.S. The most commonly encountered virus is the papilloma virus.

Viral diseases reported in the domestic rabbit:

  • Papovavirus (Shope papilloma )

  • Pox virus (Myxomatosis, Shope fibroma)

  • Adenovirus

  • Herpesvirus

  • Rotavirus (Reovirus)

  • Parvovirus

  • Calicivirus (hemorrhagic)

  • Coronavirus (diarrhea)

  • Paramyxovirus

  • Bunyavirus (Snow-shoe hare encephalitis)

6.2.1. Viral Hemorrhagic Disease (calicivirus)

Over the last 10 years there has been an increased incidence of a severe hemorrhagic enteric disease in domestic rabbits. This is caused by the rabbit calicivirus also called Rabbit hemorrhagic disease virus (RHDV). In 2000 an outbreak in the US occurred for the first time and was successfully contained. The source of the infection was not determined. Another outbreak was reported again in August 2001 without finding the source of infection (see references).

Historical perspectives and characteristics of the virus

The disease was first recognized in China (1984), but it appears to have originated in Europe (serologic evidence from 1978). It is now endemic in Asia, most parts of Europe, including Britain, and also occurs in Mexico and North Africa. The disease was seen initially in domestic (including commercial) rabbits and also wild rabbits, all Oryctolagus cuniculus. There is an overall high morbidity and mortality with possible devastating effects: in one year in Italy (1989), 64 million rabbits died of this disease. It has been suggested that the disease has been spread around the world through frozen rabbit meat from China.

The disease is caused by a calicivirus. It is antigenically similar to the calicivirus causing European brown hare syndrome (reported 1st in Sweden in the early 80's). In most locations, European brown hare syndrome appeared in hares several years before the emergence of viral hemorrhagic disease in rabbits. Most studies show that these two viruses do not cross infect hares and rabbits.

Disease in rabbits

  • The virus affects rabbits over 8 weeks of age, most often adults. Young animals appear resistant (reason unclear).

  • Incubation period is 1-3 days.

  • The disease is spread through direct contact (fecal-oral) or through contaminated feed or water, contaminated equipment, clothing, vehicles, etc. The virus is quite stable in the environment.

  • Symptoms include: depression, anorexia, respiratory signs, ataxia. Up to 100% of affected animals develop internal bleeding and die within in 1-2 days. Many animals are found dead without observing any clinical signs (peracute).

  • Peracute, acute, subacute and chronic forms of the disease exist.

  • Post-mortem findings include: hepatic necrosis, pulmonary hemorrhage, tracheal hemorrhage, petechiation on the surface of the kidneys, epicardium and endocardium (hemorrhage mostly due to DIC). More recently, cases without hemorrhage have been noted. Spenomegaly may also be seen. Virus is found in highest concentrations in the liver.

  • Diagnosis can be made at post mortem and through serology utilizing hemagglutination inhibition assays, IFA or ELISA tests.

  • Vaccination is available and effective for control of this disease in domestic rabbits. Killed vaccine is used and is protective from 5 - 15 months. It is felt that vaccinated animals may shed virus if exposed to natural infection, although they do not become ill. Vaccine is currently not available in the US.

Implications for pets, laboratory animals and wildlife

This disease is REPORTABLE to the USDA-APHIS as a foreign animal disease. To decrease potential risks for pets and lab animals in the US, discourage or ban importation of live rabbits or rabbit parts from endemic areas, possibly including frozen meat products. Recommend quarantine of any "new" rabbits to a facility for at least 1 week. Wild rabbits in the US (sylvilagus) should not be susceptible (mutation possibilities?).

Currently both New Zealand and Australia are using this virus as a form of biological control for feral oryctolagus rabbits which are classified as introduced pests in their countries. Lost agricultural production and damage to the environment is significant including destruction of flora and habitat which support important native species (wombat, bilby endangered due to the rabbit). Use of biocontrols in this manner are very controversial. For more information see Supplemental Readings.

6.3. Bacterial diseases

In contrast to viral diseases, bacterial diseases are very important in domestic rabbits. They are undoubtedly the number one cause of mortality and morbidity. The primary pathogen responsible is usually assumed to be Pasteurella multocida, however other organisms are also important and should not be overlooked.

Significant bacterial diseases of the domestic rabbit:

Pasteurella multocida

Staphylococcus aureus

Bordatella bronchiseptica (pathogenic to guinea pigs )

Clostridium piliformis (Tyzzer's disease)

Clostridium spiriforme (enterotoxemia)

Treponema cuniculi (Rabbit syphilis)

6.3.1. Pasteurella associated diseases

Pasteurella multocida is a ubiquitous organism so commonplace in domestic rabbits that it may be considered normal nasopharyngeal flora. Animals are exposed to the organism from birth onwards and will demonstrate a wide variety of diseases involving the organism at any stage of its life. Many animals of course, harbor the bacteria, but never develop disease. There are no effective vaccines for pasteurellosis in rabbits.

Diagnosis is made based on clinical signs, culture (if possible), and response to treatment. Rule-outs should include other bacteria, especially Staphylococcus aureus. Antibiotic treatment should ideally be designed based on culture and sensitivity. Specific considerations must be given to the rabbits unique response to infection and the accessibility of any antibiotics. Surgical debridement is often indicated in addition to antibiotic therapy. Prognosis for a well established infection is often poor.

Syndromes associated with Pasteurella in the domestic rabbit:

  • Septicemia

  • Snuffles - rhinitis, conjunctivitis

  • Abscesses - Dermal, Mandibular, Maxillary, Vertebral

  • Vestibular disease

  • Pneumonia

  • Urogenital disease

  • Meningitis

By far the most common form is "snuffles" which refers to an upper respiratory infection. Snuffles may begin as a conjunctivitis or a rhinitis or both. Chronic cases can lead to blocked nasolacrimal duct and eventually osteomyelitis or maxillary abscesses. A simple case of conjunctivitis or even very mild rhinitis may respond well to topical ophthalmic treatments. The nasolacrimal duct may need to be cannulated and flushed.

Rabbit with conjunctivitis
Rabbit with conjunctivitis

Conjunctivitis leading to facial abscess in a rabbit
Conjunctivitis leading to facial abscess in a rabbit

6.4. Fungal diseases

Trichophyton mentagrophytes, Ringworm, ZOONOTIC

6.5. Parasitic diseases

  • Ear mites (Psoroptes cuniculi)

  • tx. with Ivermectin, Selemectin

  • Do not aggressively debride - very painful

Ear mites
Ear mites

  • Cheyletiella parasitivorax and fleas

    • Often share with other household pets

    • Pyrethrin flea treatments effective

  • Myiasis and cuterebra

    • Hutch or outdoor bunnies are very susceptible

    • Highly sensitive to toxins (anaphylaxis if maggot ruptures during removal!)

    • Use lidocaine to paralyze the maggot

    • Monitor closely following maggot removal

    • Treat systemically with ivermectin


  • Encephalitozoon cuniculi

    • Clinical presentation of head tilt or spinal paresis

    • r/o vestibular pasteurellosis

    • tx. with fenbendazole/steroids may be effective?

    • May be zoonotic for immunosuppressed people

  • Coccidiosis (many species)

    • E. perforans and others

    • E. steidae (hepatic coccidiosis)

  • Pin worms (Passalurus ambiguus)

  • Baylisascaris procyonis

6.6. Gastrointestinal diseases

Probably the most sensitive system in the rabbit is their gastrointestinal system. Many of these problems are precipitated by diet. Consequently, close attention to dietary management will help to prevent GI disturbances, some of which are life threatening. The following conditions are the most commonly encountered.

6.6.1. Dental malocclusion

As stated above dental malocclusion, particularly of the incisor teeth is a common problem in rabbits. Malocclusion of the incisors is largely thought to be genetic, although trauma to the teeth (teeth trimming, chewing on cage wire, etc.) can also result in malocclusion.

Usually incisors (genetic)

Definitive treatment through removal of all incisors (4 upper and 2 lower), otherwise periodic trimming may be performed

Molar malocclusion is less common, but does occur and is likely the result of feeding a diet with inadequate roughage.

Special dental instrument pack very useful (see end of chapter)

See videos of dental procedures in the rabbit on TUSK

Incisor Malocclusion
Incisor Malocclusion

6.6.2. Chronic soft stools

This condition is extremely common in pet rabbits, especially house rabbits. It should be distinguished from true diarrhea which is life threatening in the rabbit. Chronic soft stools is usually related to high carbohydrate, lower fiber diet, obesity, lack of exercise, stress, or a sudden change in diet. This induces a change in gut flora resulting in the abnormal stool consistency - sticky, smallish pellets, often pasted to the perineal area. Most indoor rabbit owners notice right away since little presents are left on furniture, etc. and the odor of feces is unpleasant. If left unattended, the perineal soiling can develop into serious dermatitis, attract flies, etc. and lead to greater problems. Rabbits generally feel fine and show no signs of illness.

Treatment for this problem involves dietary correction: increasing fiber and decrease carbohydrates, decreasing stress, increasing exercise, etc. Antibiotics are contraindicated and may complicate the situation. This process is very slow, and may require quite a bit of patience and frequent bathings, cleaning up around the house!

6.6.3. Diarrhea

  • Mucoid enteropathy

Mucoid enteritis or enteropathy affects young rabbits (7-14 weeks). Anorexia, depression and accompanying diarrhea with mucous may progress to cecal impaction and death. The etiology is unknown, but is likely diet based. A high fiber, low carbohydrate diet appears to be protective.

  • Enterotoxemia -

Enterotoxemia is very serious in rabbits, usually resulting in death. Lethal toxin is produced by overgrowth of Clostridia spiriforme, (difficile or perfringens). Overgrowth can occur in young rabbits, be induced by certain antibiotics, brought on by severe stress (including surgery). Acute death with or without diarrhea is very common. Watery brown or blood tinged diarrhea may develop in some cases. Animals quickly go into shock and die. Presumptive diagnosis is based on history (stress? antibiotics?) and clinical signs. Treatment with cholestyramine and metronidazole may be attempted, along with aggressive fluid therapy and treatment for shock. Prognosis is grave.

  • Other bacterial causes of enteritis:

    • Tyzzer's disease - Clostridium piliformes

    • E.Coli

    • Salmonella

    • Pseudomonas

6.6.4. Hepatic lipidosis

Obese rabbits will necessarily deposit large amounts of fat in their liver. This change can present a problem, as in other animals, if the rabbit is suddenly starved for any reason for longer than 24 hours (e.g. hair ball, dental disease, prolonged pre or post-operative fasting). A hepatic lipidosis crisis can develop into a critical care emergency. As mentioned above, serum elevations in triglycerides and cholesterol may indicate hepatic lipidosis.

6.6.5. Hairballs (trichobezoar), gastric stasis and gastric obstruction (carpeting)

Gastric obstruction, partial and complete, is not unusual in rabbits. Gastric stasis can be brought on by many different things, including stress. Build up of material in the stomach, often palpated or seen on radiographs is not necessarily the root of the problem, but will contribute or complicate the clinical picture. Rabbits are unable to vomit and swallowed material (such as hair and carpet can easily build up if not properly digested. If motility is disrupted, the rabbit becomes dehydrated, the material condenses, becomes mucinous, the stomach wall collapses against it, and obstruction ensues.

Clinical signs are very vague, usually consisting of decreased appetite or anorexia and decreased fecal production. Like many herbivores, rabbits motility is directly related to intake. Once intake ceases, motility also ceases. Observing fecal quantity and quality (small and dry pellets) is a good indication of motility.

Diagnosis is based on history, clinical signs, physical findings, and sometimes radiographs. Radiographic findings of material in the stomach is not abnormal and should not be over interpreted. Radiographs are most useful for determining partial from complete obstruction, based on characteristic gas patterns. Surgery is indicated only for complete obstruction, partial obstructions are managed medically and constitute the majority of cases.

Medical treatment is first and foremost centered on rehydration and analgesia. The bloat causes significant pain in the rabbit, similar to a colic in a horse. Rabbits appear to be extremely sensitive to GI pain (while orthopedic pain does not appear to cause the same reaction). Use of enzymes to dissolve hairballs is controversial but appears to do no harm. The use of the enzymes is indicated as a prevention of the buildup of material but not as a treatment (comparable with a clogged sink, once the outflow is completely obstructed it is time to call the plumber (i.e. the surgeon, in our case).

Oral hydration and syringe feeding usually results in return of the rabbit's appetite in a day or two. Metoclopromide can be helpful, but is contraindicated in acute abdomen. Complete obstruction (hairball lodged in duodenum, foreign body ingestion) is a surgical emergency and carries a poor prognosis. Remember that anorexic overweight rabbits are susceptible to hepatic lipidosis and should be supported aggressively. Prevention of hairballs and gastric stasis is best achieved through proper dietary management: feeding high fiber, low carbohydrate diet, and avoiding obesity.

6.7. Pododermatitis (Sore hock)

Pododermatitis occurs in both hutch and house rabbits. It often begins with small abrasions or abnormal wear on the plantar surface of the hind feet, but can also occur on the front feet. Abrasions and wear develop into serious inflammation, eventually become infected and can progress to include osteomyelitis. The condition is extremely painful and some cases require euthanasia. Aggressive early intervention and treatment can result in a cure, but requires a strong commitment on the part of the owner. The underlying contributing factor is obesity. It is important to screen for early onset of the condition and to avoid the progressing by addressing correct husbandry. Correction of the underlying cause is essential. (see end of chapter for full description and client handout )


6.8. Hypercalcemia and calcium related diseases

Rabbits handle calcium quite differently than most other mammals. They have an extremely efficient absorption of Ca2+ at the level of the intestine. 45 - 60% of the absorbed calcium is excreted by the kidneys in contrast to most other mammals that excrete most calcium via bile and <2% by the kidneys. Vitamin D does not affect intestinal absorption of calcium in the rabbit, but may contribute to soft tissue mineralization. What appears to be a persistent hypercalcemia in a rabbit must be investigated with great care. Levels up to and including 16 mg/dl are generally acceptable. Higher levels, even up to 22 mg/dl may be seen and should be dealt with promptly.

The following calcium related conditions are commonly seen in pet rabbits:

  • Urolithiasis and cystic calculi

  • Renal calcinosis

  • Aortic mineralization

  • Metastatic calcification

Aortic mineralization in a rabbit
Aortic mineralization in a rabbit

Nutritional management appears to be helpful in preventing further development or recurrence of these conditions, but it's role is unclear. Selection of low calcium foods (See Table of Nutrient Content of Some Fruits and Vegetables), avoidance of high calcium feedstuffs such as alfalfa should be adopted, and serum calcium levels monitored closely.

6.9. Neoplastic diseases

Domestic rabbits are not particularly prone to neoplastic diseases except for female reproductive tumors. Endometrial hyperplasia often precedes the development of neoplasms. The incidence of uterine adenocarcinoma is extremely high after the age of 2 years, some say as high as 90%. Because of this, it is recommended that all females not being used for breeding be spayed by the age of 2 years. Unspayed animals should be closely examined on a regular basis for uterine tumors. Diagnosis can often be made through palpation and confirmed with an ultrasound examination. Surgical removal of tumors is recommended, but the prognosis is guarded since metastasis is common. The most commonly reported neoplasms include:

  • Uterine adenocarcinoma

  • Uterine leiomyoma or leiomyosarcoma

  • Ovarian neoplasia

  • Mammary gland neoplasia

  • Lymphoma

6.10. Health/Conservation issues in wild rabbits

Wild rabbits seen in the Wildlife Clinic are most often suffering from cat attacks. Other injuries may include: hit-by-car, or lawnmower injuries. Immature rabbits suffering from a cat attack often succumb to septicemia. Wild rabbits (cottontails) appear to be better at healing and concurring infections than their domestic European counterparts. Stress is a major problem with wild rabbits in a captive setting and may contribute to their death under these circumstances. Stress induced clostridial enterotoxemia is presumed to be the cause.

Wild rabbits have been noted with the following infectious diseases and can act as a reservoir host in many cases

  • Tuleremia (Francisella tularensis) ZOONOTIC

  • Myxomatosis/fibromatosis

  • Leptospirosis ZOONOTIC

  • Pseudorabies

  • Rocky mountain spotted fever


Critically Endangered RABBITS from IUCN

Sumatran rabbit

Helan Shan pika

Omilteme cottontail

Ochotona pallasi ssp. hamica

Ochotona thibetana ssp. sikimaria

The New England Cottontail is our local rarest rabbit species, being overtaken by the more successful Eastern Cottontail. There is some evidence that habitat fragmentation may have compromised the New England Cottontail's ability to survive.

6.11. Client Handouts

6.11.1. Client Handout - Rabbit Care - Hairball

Rabbits, like cats, groom themselves and swallow some hair while doing so. But, unlike cats, rabbits do not possess the ability to vomit. Some reasons for excessive consumption of hair include itchy skin (parasites?), lack of dietary fiber, boredom, seasonal molting, and a naturally long hair coat (Angoras). The rabbit's inability to vomit and the small pyloric lumen exiting the stomach predisposes it to hair accumulation within the stomach. The affected rabbit tends to feel full all the time and begins decreasing food intake. This is then followed by the production of smaller and smaller stools, often containing hair and eventually no stool at all. Due to the decreased caloric intake, the rabbit becomes lethargic, depressed and loses weight. If untreated, the rabbit may die from starvation or complete obstruction and rupture of the stomach. Treatment

Unless the stomach is completely obstructed and nothing can pass through it, medical treatment of hairballs will be successful. If complete obstruction occurs, emergency surgical treatment is required. A radiograph is required to make this diagnosis.

Medical treatments are intended to facilitate the breakdown and passage of the hair in the stomach. Several different medications can be given in combination to accomplish this.

  1. Enzyme treatments containing bromelein and/or papain help to breakup and dissolve the hair mass - these enzymes are found in pineapple, papaya, or in tablet form (20-100mg/day)

  2. Timothy hay adds roughage and helps carry the hair through the GI tract.

  3. Mineral oil/vaseline laxatives (cat laxatives) help to lubricate the hair.

  4. GI motility drugs such as metaclopramide or cisapride

If the rabbit is anorexic, but not completely obstructed, it is important to force feed it during this time to avoid the development of dehydration, caloric and vitamin deficiencies, and hepatic lipidosis which can be fatal. Baby food (fruit and vegetables), mixed baby cereal or blenderized pellets should be given voluntarily or by syringe. Prevention

The development of hairballs can be avoided if the rabbit is on a good diet and the owner takes precautions, especially during heavy molts. The rabbit should always have access to straw or fresh timothy hay to provide dietary fiber and promote passage of any accumulated hair through the intestine. Adequate room should be provided for daily exercise and to prevent boredom that may lead to excessive grooming. Regular administration (every one or two weeks) of a cat laxative and one of the papain preparations will help prevent the hair from building up in the stomach. These two medications should be given more frequently during heavy molts.

6.11.2. Client Handout - Rabbit Care - Sore Hock

Sore hock, pododermatitis, or foot sores are characterized by hairless, scab-covered abscessed or raw bleeding areas over weight bearing surfaces and undersides of the feet. Various factors predispose the rabbit to sore hocks including excessive body weight, reduced fur pad covering the foot soles, excessive thumping and bruising, lack of movement in a small cage, abrasions from irregular cage flooring or excessive time in the litter box. Sore hocks can occur in rabbits on both hard solid and wire floors. The incidence of sore hocks tends to increase with age and weight.

Signs for early recognition of this condition are a depressed rabbit that is reluctant to move around, usually staying confined to a cage corner. If the rabbit attempts to walk to food dishes, it tends to do so on "tip-toes". If this painful disorder is not treated, it can progress to a severe tendonitis or osteomyelitis (bone infection). Under such circumstances the rabbit may have to be humanely euthanized. Treatment

Clean and soak the foot two to three times daily with warm Betadine or Nolvasan solution and epsom salts. Dry the foot thoroughly and apply nitrofurazone powder. If the condition is severe, cushioning bandages must also be applied. The rabbit then must be kept on soft dry bedding or carpeting. The bedding must be changed often and regularly to avoid urine soaking the affected area and causing further inflammation. Systemic antibiotics may be used if the foot is grossly infected. Prevention

Keep a washable rug or a cushioned platform in a corner of the cage where the bunny can rest and prevent the bony area on the feet from coming into contact with hard or abrasive surfaces such as wooden or concrete floors or cage wire. The bedding must be kept dry and changed regularly to avoid urine burns.

7. References and Resources

Conservation Medicine Challenges [1 ]

Supplemental Readings

7.1. Professional Organizations

American Association for Laboratory Animal Science http://www.aalas.org/

Association of Exotic Mammal Veterinarians (AEMV) http://www.aemv.org/

7.2. Websites

American Rabbit Breeders Association http://www.arba.net/

House Rabbit Society http://www.rabbit.org/

7.3. Products mentioned in the text

Special rabbit/rodent dental pack is available from: Spectrum 4575 Hudson Drive Stow, OH 44224 Phone 800-444-5644 Fax 330-686-4555 spectrumsurgical.com Rabbit Dental Pack order #54-800

7.4. Articles and Texts

Lightfoot, Teresa L. ICE First Step Program 2003- Rabbits.

Abou-Madi, N. Anesthesia and analgesia of small mammals. IN Recent Advances in Veterinary Anesthesia and Analgesia: Companion Animals , Gleed R.D. and Ludders J.W. (Eds.). International Veterinary Information Service, Ithaca NY (www.ivis.org)

ACLAM Lab Animal Medicine and Science Series II CD-Rom. Great resource!!

Baker, David G. Natural pathogens of laboratory mice, rats, and rabbits and their effects on research. Clinical Microbiology Reviews, vol. 11 (2), April 1998:231-266.

Benson, Keith G. and Joanne Paul-Murphy. Clinical pathology of the domestic rabbit. IN The Veterinary Clinics of North America Exotic Animal Practice, 2:3, 1999 : 539-551.

Campagnolo, Enzo R. et al. Outbreak of rabbit hemorrhagic disease in domestic lagomorphs. JAVMA 223 (8), 2003 : 1151-1155.

Childs, James E., et al. Surveillance and spatiotemporal associations of rabies in rodents and lagomorphs in the United States, 1985-1994. Journal of Wildlife Diseases, 33 (1), 1997, pp. 20-27.

Duncan, AE, and EC Ramsay. A technique for rabbit castration. Journal of Small Exotic Animal Medicine, 2 (3), 1993, pp. 116-118.

Fowler, Murray E. and Miller, R. Eric. Zoo and Wild Animal Medicine, 5th ed. Saunders, 2003. Chapter 42.

Fox, JG, Cohen, BJ, Loew, FM. Laboratory Animal Medicine, 2nd ed. Orlando, Florida: Academic Press, 2002.

Fudge, Alan M. Laboratory Medicine, Avian and Exotic Pets. Philadelphia : W.B. Saunders Co., 2000.

Harriman, Marinell. The House Rabbit Handbook, 3rd ed. Drollery Press , 1995.

Harkness, JE, and JE Wagner. The Biology and Medicine of Rabbits and Rodents. 3rd ed. Lea & Febiger, 1989.

Quesenberry, Katherine E., James W. Carpenter, Peter Quesenberry. Ferrets, Rabbits and Rodents: Clinical Medicine and Surgery Includes Sugar Gliders and Hedgehogs. 2nd ed. Philadelphia: WB Saunders Co., c2003

Johnson-Delaney, Cathy A. Exotic Companion Medicine Handbook for Veterinarians. Wingers Pub. Inc., 1996.

Manning, PJ, DH Ringler, and CE Newcomer. The Biology of the Laboratory Rabbit. 2nd ed. Boston: Academic Press,c1994.

McTier, Tom L., et al. Efficacy and safety of topical administration of selemectin for treatment of ear mite infestation in rabbits.JAVMA 223 (3), 2003 : 322-324.

Sedgwick, CJ. Spaying the rabbit. Modern Veterinary Practice, May, 1982, pp.401-403.

Suter, C. et al. Prevention and treatment of Encephalitozoon cuniculi infection in rabbits with fenbendazole. Veterinary Record, April 14, 2001 : 478-480.

Toth, Linda A. and J.M.Krueger. Hematologic effects of exposure to three infective agents in rabbits. JAVMA, 195 (7), 1989, pp. 981-986.

Veterinary Clinics of North America. Exotic Animal Practice. Philadelphia, PA : W.B. Saunders Co., 1998-