Abscesses in Rabbits

What are abscesses?

Abscesses are one of the most common and difficult clinical problems in rabbits. They can range from open sores in the skin with white oozing pus to invasive internal lesions. Internal abscesses may go undiagnosed until they cause death of the animal and they are found on post-mortem examination. Abscesses often relate to dental problems, such as tooth root abscesses. Sometimes, pus is seen coming from the openings of the tear duct – these do not reflect eye infection but deep infection or abscessation of the tooth roots.

What causes abscesses?

The organisms generally causing these abscesses are often Pasteurella spp or Staphylococcus spp. Both can be found in healthy rabbits, particularly Pasteurellain the nasal passages and Staphylococcus on the skin. If the immune system is impaired the bacteria may take over, causing an abscess. This is a very simplified version of the events happening when an abscess forms. It may be that there are other predisposing factors, such as bone and tooth abnormalities which then lead to dental abscesses or poor ventilation which sets off respiratory problems. Regard to environmental conditions, diet and general health may, therefore, assist in prevention of abscess formation.

How are abscesses treated?

The main problem is that once an abscess occurs, it is very difficult to treat. Antibiotics find it difficult to penetrate the middle of an abscess. This means that in many cases surgery is the optimal therapy – relatively easy in a skin abscess but far more difficult in a tooth root abscess or one throughout the abdominal cavity. Unlike cats and dogs, rabbit pus is generally solid. This means that simply opening it and draining it will not be successful as the pus will not drain. Inadequate drainage or failure to remove the underlying causes results in an abscess that continuously recurs.

Where curative surgery is not possible then a range of surgeries have been attempted to control the bacteria and reduce the abscess. These include implantation of antibiotic-impregnated polymethylmethacrylate beads or antibiotic-containing dental cements. Potassium hydroxide paste has also been used as have more radical approaches, including maggot therapy. Manuka Honey too may be used; however none of these are used alone but in combination with surgical debridement. In short, the plethora of different techniques illustrates how none are totally successful in all cases.

In some recurrent cases, especially dental abscesses, there is often no alternative other than “palliative” care. This will involve regular opening and curettage of the abscess, dental therapy and continuous systemic antibiosis (to reduce risks of septicaemia) and analgesia (non-steroidal anti-inflammatories are appropriate). Some of these cases may continue in this manner for several years and maintain a good quality lifestyle.

Sadly, therapy is not always successful and if pain cannot be controlled or if expensive long-term management cannot be continued then euthanasia may be the only alternative.