What is it?
An abscess is an accumulation of pus surrounded by thickened, inflamed tissue. They occur frequently in rabbits.
Rabbit abscesses are difficult to treat because the dense inflamed wall or capsule surrounding the abscess and thick rabbit pus prevent antibiotics penetrating the infected tissue. Rabbit pus is unusual, it has the consistency of toothpaste or cottage cheese.
What causes it?
Rabbit abscesses are caused by bacteria, and occur in a number of areas:
A skin wound can result in the normal bacteria found on the skin entering the body and causing an infection; for example, after a wound (e.g. a bite). The bacteria involved are usually Pasteurella multocida, Streptococcus, Pseudomonas and Staphylococcus. Sometimes a wound can be caused by a piece of wood in a hutch and the splinter can remain. This is called a foreign body and allows entry of bacteria. An abscess with a foreign body within it can be more difficult to treat.
The weight of a rabbit carried on the feet and hocks. These areas can become chafed if bedding is constantly dirty or the floor rough. If a rabbit is overweight this is more common. Irritated skin can become inflamed and infected, causing hock sores and resulting in abscesses.
Abscesses on the face are usually caused by dental disease. Overlong tooth roots can block the tear ducts causing infection. Infected teeth can spread infection to the soft tissues and bones of the skull. The eye will often bulge painfully if there is an abscess behind, and pus may also be seen in the corner of the eye. Swelling of the lower jaw and are commonly abscesses.
An abscess in one or multiple joints can occur because of a wound or a bacterial infection affecting the whole body. They cause severe stiffness and discomfort.
These abscesses are difficult to identify as they cannot be seen externally. Any organ can be affected; but they are usually seen in the uterus, lung or liver.
What’s the risk?
Although abscesses are difficult to treat in the rabbit, they also protect the rabbit by containing the infection. If an abscess ruptured externally the pus might attract flies and result in fly strike. However, if an abscess ruptures internally there is a risk of sepsis. There is also a possibility that multiple abscesses will occur throughout the body as the infection enters the bloodstream. Multiple abscesses cause severe illness and like sepsis can be fatal.
How do you know what’s going on?
A swelling or lump is usually seen or felt. The lump may be painful, red and appear inflamed. There may be discharge if the abscess has ruptured. Hair loss can be seen and the rabbit may lick and scratch at the area. The rabbit may appear unwell or seem completely unaffected by the mass.
Internal organ abscessation cannot be seen but the rabbit may appear unwell with weight loss, a poor appetite, lethargy and hiding.
What can be done?
A veterinary examination will determine if a swelling is an abscess, cyst or tumour. The vet may aspirate the swelling to be certain. This involves piercing the swelling with a needle to confirm the presence of pus. It is important to take your rabbit to the vet as each of these conditions is best treated early.
An examination is essential to determine any underlying cause of the abscess, which must be treated. The rabbit may need blood tests to investigate their general health and an x-ray or ultrasound examination may be carried out to check internal organs.
If dental disease is suspected a skull x-ray or CT scan will identify the affected teeth. If the infection has spread to the bone causing osteomyelitis the abscess is much harder to manage.
The best treatment option is surgical removal of the whole abscess. In this way there is no chance of recurrence and no need for antibiotic use. However, it is not always possible to remove the whole abscess. For example, an abscess near the eye or a joint cannot be surgically removed without causing significant damage. Surgery may not be financially possible or the rabbit may have concurrent illness that prevents anaesthesia. Some abscesses may extend into other tissues that prevent complete removal.
In these cases, it may be possible to manage the abscess by repeatedly lancing the abscess and removing as much of the capsule as possible. The cavity must then be left open and flushed regularly to prevent it healing too quickly. Unfortunately, the abscess will often recur if the capsule is left. It is also hard to keep the area clean as rabbits need access to grass or hay. However, it can allow an affected rabbit to have a comfortable life with adequate pain relief as necessary.
Antibiotics are usually required in these cases. A section of the abscess wall is usually sent to the lab to determine the correct antibiotic. The abscess cavity may be packed with antibiotic impregnated beads that slowly release antibiotics or gauze soaked in antibacterial gels. Manuka honey can be used as an antibacterial packing or flushing agent substance.
What can I do to protect my pet?
Keep your rabbit clean and check for wounds or inflamed skin daily, particularly on the feet and hocks. The hutch and run should be well maintained with no sharp edges. Floors should be solid and smooth, wire floors damage feet and hocks. Bedding should be clean and dry.
Dental disease can be prevented by feeding 80% hay or grass, 5% pellets with the remaining 15% being made up of vegetables and treats. Regular veterinary dental checks are advisable.
Manage your rabbit’s weight as obesity increases the risk of abscesses.
Prevent overcrowding and fighting. Ensure your rabbits are bonded and not fighting over food or water.
Treat any infections promptly, chest and ear infections can progress to abscesses quickly. Wounds should be cleaned and checked daily. If they become infected, visit your vet.
Rabbit abscesses can often be treated effectively if prompt action is taken to manage any underlying cause and remove or manage the abscess.