Septic arthritis - joint inflammation
Septic (or infective) arthritis is inflammation of the joints, caused by a bacterial infection. The condition is very different to the much more commonly known osteoarthritis, which is caused by wear and tear or injury to the joints.
What causes septic arthritis?
Septic arthritis can occur after a penetrating injury near the bone. If the wound becomes infected, it can easily spread to the joint.
What signs may my rabbit show?
You may be totally unaware that your rabbit has suffered an injury. Rabbits are covered with a thick fur coat and it is often difficult to spot small injuries.
Often the first sign is a swollen joint, which may be hot to the touch and painful. The rabbit may limp or hop with an abnormal gait. As the condition is painful, the rabbit is likely to be off their food to some degree, may be lethargic and depressed.
How will my vet diagnose the problem?
In order to gain a diagnosis, your vet may recommend a radiograph (x-ray) of the affected joint to look for any obvious signs of injury. It is recommended that a swab of the wound is taken for culture and sensitivity determine which bacteria are present (there may be more than one), and the most appropriate antibiotics to use to treat the infection. Although septic arthritis is commonly caused by Pasteurella multocida and Staphylococcus spp, these are not the only bacteria that may be involved.
What treatment will be recommended?
Medical therapy involves a general anaesthetic to ‘clean out’ the joint. This involves debridement to remove the pus and infected tissue, followed by copious flushing of the joint to remove as much bacteria as possible. As rabbit pus is very thick it can be difficult to remove it effectively from the joint.
Often there is bone loss of the adjacent bones and the chance of a successful outcome is guarded. If only a digit, eg toe, is affected then amputation of the affected toe is likely to be curative and the easiest way to cure the problem. However, frequently larger joints are involved, and amputation is a last resort.
Long-term treatment with appropriate antibiotics is also often used prior to and post-surgery.
How can I prevent the condition?
By nature, rabbits like to dig, chew and most live outside. Due to this they are at risk of penetrating injures from sharp objects. Ensure that your rabbit’s environment is as safe as possible. Remove sharp pieces of wood, metal or plastic which may cause injury.
It is a wise idea to check your rabbit weekly for signs of injury, such as lumps and cuts. You will need to thoroughly part the hair to be able to see down to the skin. Run your hand along the rabbit and both sides should feel symmetrical with no clumps of wet/matted fur which can be found near an open wound. If you notice any wounds on your rabbit or are worried contact your vet as soon as possible.