by Phyllis O’Beollain, author of the Dayton Small Pets Examiner

Pasteurella multocida is a gram negative bacteria of which there are several strains. Depending upon which strain is infecting a given rabbit, the signs and symptoms can be mild or severe. Some strains will reside in the nasal tract of rabbits but do not cause any problems until the bunny is stressed or until the bunny’s immune system is compromised in some way.

Signs and symptoms of pasteurella infection (pasteurellosis) usually involve the upper respiratory tract. Infected rabbits may have a watery nasal discharge and sneezing, followed by a thick, whitish or yellowish nasal discharge. Affected rabbits may make a loud snuffling or snoring sound because of the mucous in their nose, giving rise to the lay term ‘snuffles’. As rabbits groom their faces with their front paws, these infected rabbits often have nasal discharge and mats on their front paws. Pasteurella may also cause pneumonia in the house rabbit.

Pasteurella infection can travel to the eyes, causing conjunctivitis (inflammation of the inside of the eyelids and the white of the eye) and a discharge and/or crusting around the eyes. The bacteria may also infect the ears, with resultant head shaking, scratching, loss of balance, circling, and even head tilt. Pasteurella infection may also enter the bloodstream and may cause abscesses to form under the skin, in the internal organs or in the skeletal joints.

Symptomatic pasteurella infection is usually treated with antibiotics for 14-30 days; commonly used antibiotics include include enrofloxacin (Baytril), trimethoprim sulfa, and ciprofloxacin. Antibiotics in rabbits should always be used only with strict veterinary guidance, as antibiotics wipe out the good bacteria in the rabbit gut as well as the offending bacteria that make the rabbit ill. Fluids and supplemental nutrition may need to be given to rabbits who are quite ill. Surgical drainage or excision of abscesses may be recommended as palliative care.

If the strain of Pasteurella multocida is a mild one and the rabbit has a strong immune system, it is possible that the rabbit will recover without treatment, but s/he is likely to then be a carrier, and the bacteria will take up permanent residence the nasal cavity. Under periods of stress, the rabbit is very likely to again become symptomatic. If a rabbit is infected with an aggressive strain of pasteurella (or s/he has a weakened immune system), the disease can be severe or even fatal. The best bet is to use one of the antibiotics effective against pasteurella at the first sign of infection. Infections that remain untreated for days or weeks are infections that are likely to become chronic (if the infection doesn’t kill the rabbit first). Even infections that are treated early may become chronic and require long-term treatment.

Pasteurella infection is quite contagious and can be difficult to control, so it is important to do all that you can to prevent an active infection and to obtain immediate veterinary care if your rabbit does display symptoms.

Reducing stress is very important in helping your bunny rabbit avoid active infections and to reduce the severity of the symptoms if s/he does become actively infected. Common stressors for rabbits include poor nutrition, sub-optimal living environment (including overcrowding and damp, chilly conditions), and living with aggressive rabbits or other household pets or small children who stress out the bunny. You should always provide proper housing and other living conditions for your rabbit, and this includes unlimited timothy hay and fresh water, good quality food pellets, and fresh greens daily. A cardboard box with a door cut in the side can offer a stressed or poorly rabbit a quiet place to feel safe and rest.

As the disease is quite contagious, it is best to avoid letting your rabbit come into contact with unfamiliar rabbits. The disease can be transmitted from one rabbit to another through human handling, so be sure to wash your hands in between handling rabbits and always wash your hands and clothes after handling a rabbit that is not your own.

Pasteurella can have potentially devastating effects on rabbits. Because it is so contagious and widespread, bunny owners must be vigilant to the signs of active pasteurella infection. Ongoing clinical trials seek to develop an effective vaccine against pasteurella, but in the meantime, gaining an understanding of the disease process, taking precautions to prevent it, and seeking immediately veterinary attentiion at the first signs of disease are your best bet in reducing the occurrence and severity of this ailment.

For more great articles by Phyllis, check out the Dayton Small Pets Examiner!