by Barry B. Burtis D.V.M.
Rabbits are one of the most popular pets these days. There are a variety of reasons for this and last time, in this column, some of them were discussed. This time we will turn our attention to some of the health concerns of bunnies.
They do not require vaccinations and, in general, they are quite healthy little animals. Digestive upsets are able to be reduced as a risk, if strict adherence to a proper diet is maintained. Unfortunately, rabbits are very susceptible to one particular type of bacteria, called Pasteurella multocida, and it is responsible for a number of their health problems.
Respiratory disease is one of the more common health problems that can affect rabbits. Pasteurellosis is the primary respiratory disease that affects domestic rabbits and it is caused by an infection with that troublesome bacteria, P. multocida. The term "snuffles" is often used to name this upper respiratory disorder in rabbits. A clear, watery discharge from the nostrils usually precedes a white or yellowish mucopurulent discharge, as the problem begins. Affected individuals may have bouts of sneezing and make loud breathing noises through their nose. Conjunctivitis, often called "pink eye", frequently occurs as a part of the problem. If the tear ducts become blocked as a result of the swelling and inflammation in the area, it causes more complications. Excessive tearing from the eyes overflows and causes scalding of the face, hair loss and skin infection in the area below the eyes.
Middle or inner ear infections are other problems experienced by rabbits that are most often the result of a Pasteurella infection. With middle ear infections, more frequent shaking of the head or scratching at the ears may be noticed. Occasionally few symptoms are noticed. However, if the infection moves deeper to involve the inner ear, severe changes occur. A head tilt along with a profound loss of balance and equilibrium and irregular eye movements, known as nystagmus, develops. The bunny usually is unable to stand and often rolls uncontrollably when it attempts to move or change position.
Abscesses below the skin, in the space behind the eyes and in the internal organs, bones, joints and genitalia also can be caused by P. multocida. These abscesses are thick walled, contain a thick white exudate that does not drain and slowly enlarge. Often, they develop on the jaw.
Some strains of P. multocida are able to enter the bloodstream of infected rabbits and rapidly spread throughout the body. This causes acute generalized disease, fever and sudden death. There is a more chronic form of this syndrome that develops often long after the acute phase. Abscesses can form in or around the heart and lungs causing pneumonia, pleuritis and pericarditis.
The major problem is that rabbits appear to be very susceptible to the Pasteurella bacteria. It's likely almost all rabbits harbour the bacteria in their bodies. They become infected from their environment or other rabbis when they are very young. The bacteria can remain subclinical or dormant in their systems until some stress, illness or other factor allows the bacteria to flare up, causing one or more of the problems listed. Treatment of the conditions discussed with antibiotics will usually result in improvement, but seldom can the bacteria be totally eliminated from an infected rabbit. This leads to an increased risk of recurrence of the disease.
The prevalence of this group of diseases in the rabbit population means it is very important that prompt veterinary care be sought for any bunny showing signs of illness.Barry Burtis is a local companion animal veterinarian. Past Pet Tales can be found at www.baycitiesanimalhospital.ca