Arthritis is inflammation of the joints and it has many causes. In rabbits, arthritis is most commonly seen as a painful degenerative condition affecting older animals. Pain can be difficult to detect in rabbits, so careful observation of behaviour is important to ensure rapid and humane treatment.
What is arthritis?
Arthritis is a general term given to the inflammation of the joints. Inflammation is the body's way of responding to disease and irritants. The signs of inflammation are redness, heat, swelling, and pain. Any joints within the body can be affected by arthritis.
What causes arthritis?
Arthritis has many causes but the most commonly detected type of arthritis in rabbits is due to age degeneration of the joint structure, commonly known as osteoarthritis. With osteoarthritis, the cartilage in the joints can wear away, removing the cushioning layer of tissues that helps protect the joints during movement. The result is bone rubbing against bone causing inflammation, pain, swelling, and stiffness. Heavy breeds and overweight rabbits are more at risk of osteoarthritis due to the increased strain on the joints, as well as animals that have lost limbs (causing extra strain on the remaining limbs).
There are many other causes of arthritis, including autoimmune disease (where the body 'attacks' itself resulting in joint deterioration), and infectious arthritis (caused by a bacteria, virus or pathogen entering the joint and causing inflammation). Infectious (septic) arthritis can occur at any age and in any breed of rabbit. If a rabbit contracts an infection in another area of the body (such as with dental disease or an upper respiratory tract infection), there might be an increased risk of bacteria migrating to the joint, causing septic arthritis.
What signs might my rabbit show?
As your rabbit ages, degenerative arthritis may set in and you may start to see signs of pain such as your rabbit slowing down and not as active as it used to be. This can creep up very slowly, making recognising and diagnosing arthritis quite difficult on clinical signs alone.
Other signs of pain may include your rabbit having difficulty getting in and out of the litter tray, getting up or hopping around. Your rabbit may struggle to move around, present an abnormal gait or have difficulty grooming, leading to an unkempt coat or a mucky bottom. Your rabbit may not be able to scratch its ears, so excess amounts of earwax may accumulate. Urine scalding may develop in some cases. Sometimes subtle behavioural changes, such as being quieter than usual or aggressive when handled, are also an indication of discomfort or pain. Less commonly, reduced appetite may also be seen. If you notice any of these signs, you should consider taking your rabbit to the vet as they may all indicate signs of being unwell and may also indicate the onset of arthritis.
How is arthritis diagnosed?
Your vet will give your rabbit a full clinical examination. Radiographs may be used to confirm or rule out the presence of arthritis. Your rabbit will probably require sedation or general anaesthesia in order to achieve good enough images to be diagnostic.
Other more sophisticated diagnostic imaging techniques, including ultrasound, computed tomography (CT), magnetic resonance imaging (MRI) and arthroscopy, can also be used for a more accurate diagnosis. All these techniques can prove very useful to visualize the degree of bone and joint destruction.
Your vet may also do a blood test, urine test, or take a sample of joint fluid (joint aspirate) to test in the lab to rule out any underlying problems such as infection.
Can my rabbit be treated for arthritis?
It is possible to treat arthritis in rabbits in order to try and ease some of the discomfort and difficulties that the rabbit may be experiencing, but it is not currently possible to cure the problem completely.
Non-steroidal anti-inflammatory drugs (NSAIDs) are commonly used in rabbits to reduce inflammation around the joints and to ease the pain and discomfort that is usually present with the condition. Your vet may want to check your rabbit's liver and kidney function before prescribing these medications, especially if long-term treatment is required.
Septic arthritis can be resolved if caught and treated early enough. Usually, antibiotics are prescribed to treat the underlying infection.
There has been controversy regarding supplementation of products that promote joint health in both humans and animals. There are some rabbit foods that now contain added glucosamine, which is thought to benefit animals with arthritis and help with joint mobility; however, the research is still inconclusive about whether these actually make a significant difference to pain and disease progression.
While it can be tempting to reduce mobility in a rabbit that seems painful when it moves, gentle exercise will help keep muscles supple, and joints free from stiffness. Keeping a lean but healthy body weight and following a regular exercise routine is helpful in maintaining joint mobility.
For rabbits that refuse to move, consult with your veterinarian about care recommendations.
If your rabbit is very reluctant to move, provide a nest area with soft absorbent bedding to prevent soiling and pressure sores. Keep in mind that deep bedding may provide further challenges for your rabbit to move around in, so have an area of the enclosure where the rabbit can walk with ease.
For rabbits who are soiling their fur and bedding, you may need to clip the fur around the hind end to prevent the skin from being damaged by urine scalding, or build-up of faecal matter. Gentle massage over the muscle of the affected area can help encourage blood flow to the joints and decrease the degree of muscle tightness. Gently flexing and extending the affected joint for a few minutes several times daily may help as well, but always remember that physical therapy may be detrimental in cases of trauma. Always follow your vet's recommendation in these cases.
Your rabbits litter tray will need to have a low entrance if it is having difficulty hopping in and out, and if your rabbit has a ramp in their hutch/run or stairs, then you may need to make other arrangements as they may struggle to use these.
Some rabbits may not be able to reach their caecotrophs, so it is a good idea to collect them and place them in, or near to, their food area as most rabbits will eat them on their own.
What measures can I take to help my rabbit?
Preventing arthritis isn't always possible but maintaining a healthy diet and exercise regimen may be helpful in maintaining healthy body condition. Ensure that you do not allow your rabbit to become overweight.
If you think your rabbit may be developing arthritis (symptoms can be attributed to other conditions), then take your rabbit to see your vet as soon as possible.