HRS Article: Rabbit Abscesses
Q. My rabbit has an abcess on his shoulder. My veterinarian has him on Baytril tablets and I am swabbing it to keep it clean. Am I doing all I can for him?
A. This is an excellent question about a common problem that afflicts the pet rabbit. An abscess is a cavity containing pus, surrounded by inflamed tissue that is usually the result of a bacterial infection. In humans, abscesses of the skin are often caused by Staphylococcus spp infections, but in rabbits, abscesses can be caused by a wide variety of bacteria including Pasteurella multocida, Streptococcus spp, Pseudomonas spp and Staphylococcus spp. One should not assume all infections in rabbits are caused by Pasteurella acteria. This has to be proven with a positive bacterial culture.
Rabbits can form abscesses in nearly any organ of the body and in skin and bone. The most common causes of rabbit abscesses are bite wounds that become infected, tooth root infections and tear duct infections. Tooth root and tear duct infections lead to abscesses on the face and head. Rabbits do not form liquid pus that drains easily when the abscess is lanced. Rabbit pus is very thick, about the consistency of toothpaste, because there is an enzyme missing that can break the necrotic debris into a more liquid form. The consistency of the pus makes it difficult to clean it thoroughly from a wound. In addition, it is not uncommon for a rabbit abscess to develop finger-like projections over time. These can spill into surrounding tissue extending the infection. It is exceedingly difficult to keep these infected “tracks” clean. There are many thoughts on how best to handle rabbit abscesses and much depends on the location of the infection, the cause of the infection and the general condition of the pet. I can not stress enough, that no matter what treatment is chosen, it is vital to maintain your rabbit on a healthy diet high in fiber and low in starches and fats, allow daily exercise and a clean environment to enable the immune system to work at its maximum capacity.It may be necessary to perform diagnostic tests to investigate the cause of the abscess, such as radiographs of the head, chest or abdomen, and blood tests to determine the response of the immune system and the condition of other organs.
No matter what treatment is selected, rabbit abscesses have a higher probability of coming back than abscesses in cats, dogs or humans. This is do to such things as the thick, tenacious nature of the pus, the propensity for abscesses to invade surrounding tissue with finger-like tracks, and because the cause of the abscess (such as a tooth root infection) may not be taken care of. Most veterinarians experienced with rabbits agree that the most aggressive approach possible provides the best chance for a complete cure. By that I mean to surgically remove the entire abscess, including any underlying diseased tissue that might have been the source of the infection. In addition, it is advisable to have the wall of the abscess cultured to determine the bacteria responsible for the infection and thus determine the best antibiotics to use against it.
It is not always possible to surgically remove an abscess due to its location, other disease in the pet (making anesthesia or lengthy surgery dangerous) or restraints on the finances of the caretaker. In these cases the abscess can be opened, cleaned out thoroughly and flushed with an antiseptic solution. Usually, this procedure is carried out under anesthesia, unless the abscess is very small. The wall of the abscess can be cultured, as described previously. These wounds must be left open to be flushed at least twice a day for several weeks. If the abscess closes too quickly, it will merely fill up with pus again. Other accepted methods of dealing with lanced abscesses include packing caustic material into the cleaned cavity to kill the bacteria, and injecting the wall of the abscess with antibiotics on a weekly basis.
Some rabbits can live with abscesses on various parts of their body for years by having them surgically drained as needed. Rabbits are very good at forming a thick capsule around the infected tissue effectively “walling it off” from the rest of the body. If the abscess is not causing pain, the rabbit may act as if nothing is wrong. This does not mean that if you see a lump on your rabbit’s body that you can ignore it. Any unusual lumps or masses should be investigated by your veterinarian as soon as possible. However, some rabbits that have had repeated treatment for recurring abscess learn to live comfortably with them and should not be euthanized because they don’t “look” normal.
All abscess cases will require oral or injectable antibiotics. If the entire abscess is removed, then the antibiotics might be used for seven to 10 days.