Care of Rabbits
The domestic rabbit (Oryctolagus cuniculus) was historically used for fur and meat, as well as for medical research. Today, rabbits are popular as pets because of their loveable nature and relative ease of care. Rabbits are not rodents but lagomorphs. The identifying characteristic of lagomorphs is that they possess a double row of upper incisor teeth whereas rodents only have one row. Similar to rodents, lagomorph teeth grow continuously throughout life.
Female rabbits are termed does, males are termed bucks, and babies are called kits. The age at which sexual maturity is reached varies considerably among breeds and is dependent on age as well as body weight. In general, small breeds are mature at 4 to 5 months of age, medium breeds at 4 to 6 months of age, and large breeds at 5 to 8 months of age. Reproductive life of a rabbit is between 3 and 6 years, depending on gender and breed. Average gestation length is 30 to 33 days. Litter size depends on breed. Kits are born blind, hairless, and helpless and nurse only once a day for approximately 3 weeks, at which time they begin to venture from the nest and eat solid food. Rabbits are fastidious breeders so spaying and neutering is recommended. Aside from providing birth control, spaying a female rabbit can prevent uterine cancer while neutering a male can lessen aggression and urine spraying.
Rabbit nutrition is relatively simple, yet there are important issues to consider. First, rabbits have one of the highest water requirements of any animal so abundant fresh water is a must. Second, obesity is common in pet rabbits due to overfeeding of pelleted food. Rabbit pellets should be offered at ¼ cup per 5 pounds of body weight daily. Also, commercial rabbit pellets with added nuts and other “goodies” of low nutritional value should be avoided. Pellets should be purchased in small quantities and stored in air-tight containers to avoid spoilage. Rabbits will often tip food bowls and refuse to eat if pellets are rancid. Finally, rabbits lack the ability to vomit. Consequently, a seemingly simple problem such as hairball formation can turn into a medical emergency. Hair can build up in the stomach leaving little room for food, and hairballs can even obstruct the intestinal tract. To help normalize gastrointestinal motility, hay should be available at all times. This is thought to keep hair from adhering together and keep it moving through the GI tract. Timothy, brome, or prairie hay is preferred. Alfalfa and clover hay should be avoided as they are not appropriately nutritionally balanced. The free-choice feeding of hay also prevents obesity and aids in proper fermentation of gastrointestinal bacteria. Fresh vegetables can be offered as an occasional treat. Oxbow Hay Company offers a full line of products and can be contacted at www.oxbowhay.com or 1-800-249-0366. Fresh leafy greens can also be offered daily (e.g. romaine lettuce, kale, collard greens, parsley, mustard greens, and pesticide-free dandelion greens).
Rabbits can be housed in commercial or custom-designed hutches, indoors or outdoors. Most manufactured hutches are a combination of wood and metal. Despite the design, cages should allow for ample movement (at least 3 hops) and provide escape from urine and feces. Most rabbits do well on wire flooring designed to allow feces and urine to fall through, although at least a portion of the cage should have a solid floor so as to avoid foot irritation. Care must be taken to keep the floor surfaces clean to avoid foot infections. Also pay special attention to the space between each wire as feet can become lodged if the space is not appropriate for the size of rabbit. If used, bedding should be free of dust and perfumes or aromatic oils. Avoid cedar as it is too aromatic and can irritate the respiratory tract. Be aware that natural wood shavings can come infested with microscopic mites. Recycled paper products work extremely well and are very absorbent (e.g. Yesterday’s News cat litterâ). Outdoor rabbits should be sheltered from wind, rain, and direct sunlight. Because they cannot sweat and panting is ineffective for dissipation of heat, rabbits are intolerant of warm temperatures. Temperatures above 82 ° F can be harmful, if not fatal, and high humidity compounds the situation.
Diseases of Rabbits
Ectoparasites – Included are fleas, ticks, fur mites, and ear mites. All cause some degree of irritation and have the potential to cause serious secondary diseases like skin infection, anemia (fleas), and ear infection (ear mites). Diagnosis is based on gross or microscopic examination. Type and length of treatment depends on the parasite but include topical or injectable parasiticides.
Endoparasites – Coccidia is the most common intestinal parasite of rabbits, and some species of the parasite can cause liver damage. Other intestinal parasites include Giardia (a protozoan), tapeworms, pinworms, as well as others. Symptoms can range from none to diarrhea and systemic illness. Diagnosis is based on microscopic examination of the feces. Type and length of treatment depends on the parasite.
Maggot infestation – Any rabbit that spends time outside should be checked daily for evidence of maggots, especially around the anus. Flies are attracted to the smell of feces and will lay eggs on the skin of the rabbit. Eggs hatch within hours and the maggots begin to burrow under the skin, cause serious tissue damage, and infection occurs very rapidly; infection can become severe enough to be life threatening. Any suspicion of maggot infestation should be taken seriously and the rabbit should be evaluated by a veterinarian for diagnosis and treatment.
Trichobezoars – Otherwise known as hairballs, trichobezoars can cause serious illness and even death. Rabbits do not have the ability to vomit so ingested hair can accumulate in the stomach or obstruct the intestinal tract. Symptoms include anorexia, bloating, lethargy, decreased or no stool production, and even sudden death. Diagnosis can be difficult but nutritional history and abdominal xrays provide useful information. Treatment varies according to severity of illness. Supportive care consisting of fluid therapy, nutritional support, and antibiotics are often necessary. Surgery is required for cases in which an intestinal obstruction is confirmed or suspected. Prevention is aimed at inhibiting hairball formation. Regular brushing can reduce the amount of ingested hair. Feeding free choice hay regulates gastrointestinal motility and can aid in the passage of hair through the GI tract. Offering fresh pineapple juice provides enzymes (bromelain, papain) believed to inhibit clumping of hair in the stomach. Offer 2 tablespoons by mouth daily for 2 to 4 days every 2 months. Pasteurization of the juice renders the enzymes inactive, so the juice must be fresh. Commercially available papain tablets can be found in some pet stores and can be offered at 1 or 2 tablets by mouth daily for 3 to 5 days every 2 months. Feline hairball remedy ointments can also be used.
Abscesses – Abscesses can involve the skin, tooth roots, or internal organs. Because of the nature of the pus formed, antibiotic therapy alone is not successful. Thus, treatment of skin abscesses involves surgical excision (removal) followed by oral antibiotic therapy. Tooth root abscesses must be approached by extraction of the affected tooth or teeth and oral antibiotic therapy. Abscesses of internal organs can be difficult to manage depending on the organ affected.
Pododermatitis – Also called “sore hocks”, infection of the skin of the feet can occur in any rabbit, but is more common in rabbits housed on wire mesh floors that are not kept clean of feces and urine. Treatment involves antibiotic therapy and, if severe, surgical cleaning and treatment of the wounds.
Otitis – Ear infections can occur in any portion of the ear canal (external, middle, or internal) although middle or internal ear infections are more common. Typically, the infection originates in the sinuses and ascends the eustachian tubes to the ear canal. Signs of middle ear infections may be difficult to notice but should be suspected if the rabbit scratches excessively at the base of the ear. As the disease progresses to include the inner ear, a head tilt develops along with other neurological signs (circling or rolling when attempting to walk). Infections can be severe enough to extend into the brain. Long-term treatment with antibiotics is often necessary to clear the infection. In some instances, the infection is never cleared, but it may regress enough so as to relieve symptoms.
Dental disease – Dental disease in rabbits is usually limited to overgrown teeth due to malocclusion (misalignment of the jaws). Oral abcesses can result from overgrown roots or oral trauma from elongated teeth. Starvation from inability to grab and chew food is a potential consequence of malocclusion. Treatment includes trimming or filing the teeth under anesthesia or extracting the overgrown teeth.
Reproductive tract disease – Female rabbits are at increased risk for developing uterine cancer, especially if not spayed before puberty. Mammary gland tumors and uterine infections are not uncommon. Reproductive tract disease in males is rare. Spaying and neutering rabbits is strongly suggested, not only to control unwanted litters, but to avoid future health problems.
Urinary tract disease – Urinary tract infections (UTI’s) can occur in rabbits, as can bladder/kidney stones and crystals. UTI’s are more common in females than males. Although rabbit urine can periodically have an orange/pinkish tinge, bloody urine can look similar. The only way to differentiate is to have a urinalysis performed. Oral antibiotics are used to treat UTI’s. As for bladder/kidney stones, formation is typically secondary to feeding too much alfalfa or other foods with a high calcium content. The urine takes on a milky appearance. X-rays are necessary to rule out the presence of stones so that proper treatment can be initiated. Bladder stones require surgical removal. Unfortunately, kidney stones are inoperable. Correcting nutritional imbalances is important for prevention.
Orthopedic disease – Broken bones are not uncommon in rabbits, especially in those who are allowed to roam without supervision. Treatment depends on the severity of the fracture. Back injuries also occur with relative frequency, usually as a result of improper restraint. Never pick up a rabbit without supporting the hindquarters. One forceful kick can result in a broken spine and permanent injury or paralysis. Always place a rabbit back into its cage backward. If placed head first, the rabbit will want to jump into the cage and could injure its back.
Respiratory disease – Upper respiratory infection (“snuffles”) in rabbits is typically caused by Pasteurella multocida bacteria, although there are other organisms that can be responsible. Pasteurella species can cause infections almost anywhere in the body (ear, reproductive tract, central nervous system, lungs) and can be difficult if not impossible to clear. Most rabbits sold in the pet trade carry Pasteurella and it can be difficult to determine which rabbits will succumb to illness. New serologic tests are being developed that can help identify acute or chronic carrier states. Signs of respiratory infection include increased respiratory effort, nasal discharge, matted fur on the front legs (from cleaning a dirty nose), inappetance and lethargy. Treatment is more successful if initiated early in the course of the disease and involves prolonged antibiotic therapy and, occasionally, hospitalization and supportive care.
*The above list of diseases is not all inclusive but was prepared to provide rabbit owners information about some of the more common illnesses and how to recognize them.