What are some common diseases of pet rabbits and their signs?
Common conditions of pet rabbits include upper respiratory tract infections (snuffles), internal and external parasites, dental disease, gastrointestinal (GI) stasis, Encephalitozoon cuniculi, uterine problems (infections or cancer), and pododermatitis (foot sores or sore hocks).
Respiratory tract infections
Snuffles is the common name of an upper respiratory tract infection often caused by bacteria. Pasteurella multocida is the most common bacterial organism, causing upper respiratory infections in rabbits. Most commonly, clinical signs are related to the eyes (mucus or pus-like discharge, redness, squinting) or nose and sinuses (sneezing, mucus, or pus-like discharge). The eyes and nose are both commonly affected. Crusty, matted fur is often seen on the inside of the front paws as a result of the rabbit rubbing its eyes and nose to remove the mucoid discharge.
Pasteurella multocida can infect other areas of the body, as well. Ear infections (resulting in a head tilt), abscesses (lumps on the body), pneumonia (bacterial infection of the lungs), and uterine infections (often only diagnosed during exploratory surgery) may be seen. Sudden death from septicemia (bacterial invasion of the bloodstream) is rare but can occur.
Rabbits can become infected with various intestinal parasites (coccidia and pinworms are common), as well as external parasites such as ear mites and fur mites. Depending on the region of the country you live in, fleas and ticks may become a serious infestation for rabbits that live outside.
Regular veterinary check-ups, including microscopic fecal examinations at least once a year, enable early diagnosis and treatment. See handouts "Pinworms in Rabbits," "Coccidia in Rabbits," and "Fleas in Rabbits" for more information.
Rabbits’ teeth grow continuously, but the daily act of chewing food helps wear their teeth down at a rate equal to their growth, as does chewing on wooden blocks, branches, and toys. Regular chewing of high fiber food, such as hay, helps keep the teeth at a consistent, functional length.
Occasionally, tooth or jaw trauma or disease will change the way the teeth grow, causing misalignment of the upper and lower jaws and overgrowth of teeth. In some cases, rabbits are genetically predisposed to poor teeth alignment. When teeth become misaligned, they no longer meet and will not wear each other down during chewing. Both the cheek teeth (premolar and molar teeth) and the incisors (the big teeth at the front of the mouth) can be affected.
"Rabbits with overgrown teeth may stop eating, grind their teeth in pain, drool excessively,
drop food from their mouths, and lose weight."
Rabbits with overgrown teeth may stop eating, grind their teeth in pain, drool excessively, drop food from their mouths, and lose weight. You can easily detect a problem with the incisors by lifting the rabbit’s lips up and looking into their mouth. A veterinarian familiar with rabbits can use special instruments to assess the cheek teeth, further back in the mouth, to diagnose problems with these teeth. See handout "Dental Disease in Rabbits" for more information.
Gastrointestinal (GI) stasis
When a rabbit stops eating, for whatever reason (dental disease, stress, or respiratory tract infection), the normal bacteria that ferment and digest food in the GI tract can be overtaken by overgrowth of painful, gas and/or toxin-producing bacteria. This condition further suppresses the rabbit’s appetite, making the problem more critical and, in many cases, can lead to death if left untreated.
This condition, known as GI stasis, is common in rabbits and can be successfully treated by your veterinarian if diagnosed early. Newer research has also drawn an association with Encephalitozoon cuniculi as a cause for recurring GI stasis cases. Once a rabbit becomes dehydrated and inactive, the condition will become life threatening.
Treatment includes fluid therapy (subcutaneous or intravenously), syringe feeding, anti-inflammatory medication and analgesics (pain relief). GI motility-enhancing drugs will be used once fecal production resumes.
Encephalitozoon cuniculi is a common disease that has affected rabbits for decades. This disease, caused by a microsporidian parasite, can cause a wide range of illnesses in rabbits. The most common clinical picture is when a rabbit presents with a head tilt. This condition is caused by an inflammatory infection in the brain. In advanced cases, the neurological imbalance causes the rabbit to be very unsteady and begin rolling.
In a separate clinical manifestation, rabbits with this disease may develop large, white, fluffy material in the anterior chamber of one eye (the fluid-filled front part of the eye between the cornea and iris). This ocular infection can be treated, but the material will remain in the eye permanently.
E. cuniculi can also cause severe kidney (renal) disease. The infection causes permanent kidney damage and, in many cases, can become a fatal infection. These cases usually cause gradual weight loss, dehydration, and eventual kidney failure if left untreated.
Lastly, there is now documentation that E. cuniculi can infect the spinal cord and may affect the nerves that help the stomach digest food. In these infections, the rabbit will show recurring GI stasis.
Like dogs and cats, female rabbits should be spayed early in life (by 5-6 months of age) to prevent uterine infections and cancer. Intact (un-spayed) female rabbits over 3 years of age are at high risk for developing ovarian, uterine, or mammary cancer. Uterine adenocarcinoma should be suspected any time an un-spayed female rabbit has bloody vaginal discharge.
"Uterine cancer is completely preventable by spaying the rabbit early in life."
Your veterinarian can diagnose uterine cancer by palpating (feeling) an enlarged uterus or identifying an enlarged/thickened uterus on ultrasound or on X-rays. Definitive diagnosis is typically only made during exploratory surgery to remove the uterus. Uterine cancer is completely preventable by spaying the rabbit early in life and is often completely treatable if the diseased uterus is removed surgically before the cancer spreads to the rest of the body (see handout "Spaying Rabbits" for more information on this procedure).
In select cases, intact females can also develop mammary gland cancer, the most common of which is mammary gland adenocarcinoma. This cancer causes large, firm swellings/nodules on the breasts of the female rabbit.
Pododermatitis or “sore hocks” is a common condition in rabbits. The hocks are the rabbit’s ankles. When a rabbit is sitting, which it does most of the time, its hocks are in contact with the floor of its cage. Often, wire-floored cages are too rough on the hocks, causing the protective fur layer on the sole of the foot and the hock to wear thin. When this occurs, the skin turns red and becomes ulcerated and painful.
The condition is usually prevented by taking the rabbit off the wire-bottom cage entirely and housing them on smooth-bottomed cages with ample soft bedding and a litter box. Rabbits that must live in wire cages should be provided with bedding and a section of cage floor that is smooth (such as wood, plastic, or Plexiglas), so that the rabbit can take the pressure off its feet. Recycled or shredded paper and timothy hay make great bedding. Replace bedding every 2-3 days to prevent bacteria from building up, as this may also irritate the feet.
How can I tell if my rabbit is sick?
Some signs of disease in rabbits may be specific for certain conditions. More commonly, however, signs are vague and non-specific, such as lack of appetite and lethargy, which can occur with many diseases including GI stasis, uterine cancer, and even kidney or liver failure. Drooling or slobbers from dental disease may be noted as matted and discolored hair at the corners of the mouth or under the chin.
Any sign of neurological imbalance or head tilt needs immediate attention. Weight loss is also a concern that always needs prompt attention by a rabbit-savvy veterinarian.
You should be concerned if your rabbit’s appetite deviates at all from normal and you should take your rabbit to your veterinarian immediately for an evaluation. If a rabbit misses even one meal, this is a cause for concern and should be promptly investigated.
How are these diseases treated?
Respiratory tract infections
Many cases of snuffles are mild and, if caught early, can be managed or cured. If left untreated, particularly if the bacteria causing the problem is rapidly growing, this disease can be severe, chronic, and potentially fatal. A swab of ocular or nasal discharge for bacterial culture and antibiotic sensitivity testing should be taken to help guide treatment.
Treatment involves either oral or injectable antibiotics, given for a minimum of 2-4 weeks, plus an oral anti-inflammatory drug and syringe feeding if the rabbit is not eating well on their own. In some cases, treatment may be necessary for months depending on the response to therapy.
Certain oral antibiotics, especially oral penicillin and similar drugs, can cause a fatal dysbiosis (imbalance of intestinal bacteria) in rabbits, as they upset their normal GI bacteria and cause serious diarrhea and dehydration. There are certain oral and injectable antibiotics that can be safely used in rabbits with respiratory tract infections, but none is a sure cure. Eye drops and nose drops may be used in conjunction with oral antibiotics as prescribed by your veterinarian. Medications used for dogs, cats, or other pets can cause serious side effects for rabbits. Never self-medicate your rabbit.
Pasteurella organisms are normal inhabitants of rabbits’ nasal passages, but the immune system usually keeps the organisms in check, so only some rabbits manifest disease from these organisms. Stresses may trigger clinical signs from Pasteurella bacteria (improper diet, change in diet, introduction of a new pet, overcrowding, environmental stresses, immunosuppression, or the presence of other disease).
"It is critical to feed your rabbit a balanced diet and keep their environment
clean and stress-free to minimize the chance for infection."
The disease is easily transmitted by close contact between rabbits. If the Pasteurella bacteria invades the nasal sinuses or the bones of the skull, surgical intervention will be necessary. Aggressive antibiotic therapy may be required and, in many cases, the infection becomes chronic (recurring).
Ideally, new rabbits should be isolated (for a minimum of one month) before introducing them to existing pets. Litter should be changed every 24-48 hours to prevent ammonia accumulation from urine, which can irritate the eyes and nasal tissue, making the rabbit more susceptible to bacterial infection. Relapses may occur if your rabbit is exposed to stressful situations. It is critical to feed your rabbit a balanced diet and keep their environment clean and stress-free to minimize the chance for infection.
External and internal parasites are common in rabbits and are usually easily treated. The medication your veterinarian prescribes will depend on the type of parasite and the presence of secondary infections. Veterinarians check for gastrointestinal parasites by performing a microscopic examination of the feces; they check for skin and haircoat parasites by performing a microscopic examination of a skin sample or an ear discharge swab. Oral medications are usually prescribed to treat internal parasites. Oral medication, topical medication, shampoos, and/or environmental treatments may be necessary to treat external parasites, depending on the type.
One skin mite, Cheyletiella, or walking dandruff, can be very challenging to eliminate, as it persists in the environment and is transmittable to people (see handout "Walking Dandruff in Rabbits" for more information). The environment and the pet must be treated simultaneously, and anyone who has been in contact with an infected rabbit and who develops skin lesions should seek the advice of a physician.
E. cuniculi infections first need confirmation by a blood test sent to a reference lab to make sure the symptoms are due to this organism. Once the diagnosis is confirmed, an anti-protozoal drug will be prescribed. In cases involving head tilt or rolling, anti-inflammatory and vertigo-type medications will be helpful. Cases that affect the eye will need the anti-protozoal medication and anti-inflammatory medication. Cases that involve the kidneys or GI stasis will often require hospitalization, IV fluids, and anti-protozoal medication. Some cases are very difficult to resolve, even with treatment. This organism can infect humans and other pets. It is also well known that some rabbits are carriers and never show symptoms. The organism is transmitted when a rabbit ingests urine from infected rabbits.
Overgrown incisors or cheek teeth must be managed by a veterinarian who uses a dental instrument to file or grind down the overgrown teeth, usually with the rabbit under anesthesia. Tooth filing will often need to be repeated at regular intervals, as the teeth continue to grow throughout the rabbit's life.
Clipping the teeth with nail trimmers or wire cutters, once a popular treatment, is no longer recommended because the incisors can easily break, resulting in pain and infection. Rabbit veterinarians now have special dental burs and drills to safely trim a rabbit’s teeth. If your rabbit has chronically overgrown teeth and needs repeated teeth trims, you may wish to discuss with your veterinarian the option of having problem teeth removed under general anesthesia.
Uterine adenocarcinoma is treated surgically by spaying the rabbit (ovario-hysterectomy). The cost of the procedure will be higher when the rabbit is sick (rabbits with uterine cancer may need intensive care such as hospitalization, fluid therapy, and force-feeding), hence early spaying, to prevent the problem from developing, is recommended. Uterine infections may also require spaying, in addition to antibiotic treatment.
Treatment of pododermatitis can be difficult and challenging, especially in the later stages of the condition, when infection has spread through the skin into underlying muscle, tendons, and bones. Treatment requires antibacterial medications to control the infection, coupled with cleaning and bandaging the sores on the hocks. Soft bedding is essential to allow the sores to heal. When caught early, the hocks can usually be treated, and the condition can resolve. However, when left untreated, this condition can invade deeper tissues or the hock joint. In many cases, amputation is necessary to completely remove the infected tissues and prevent invasion into bones or bloodstream.