The cruciate ligaments are key structures that stabilize the stifle (knee) joint. Each joint has two cruciate, or cruciform, ligaments, so-called because they are arranged in a crossed formation. In all species, including rabbits, they can be injured by trauma, usually from twisting or overstretching the leg.

An x-ray of a normal healthy knee joint ©Vetstream Ltd

A rabbit’s natural gait is to propel itself with the two powerful hind legs at the same time, to produce the well-known hopping motion. Rabbits also jump and leap in the air when they are happy, known as ‘binkying’ or doing ‘binkies’. These movements, whilst normal for rabbits, can result in injury, especially in overweight rabbits and larger breeds, due to the fact there is more weight on the joint and ligaments which stabilize the joint. Older rabbits, which may have some weakness in the ligaments, are also more prone, and injuries can happen to any rabbit if they fall or are dropped.

We need to always remember that as a prey animal rabbits will always hide signs of illness and injury for as long as possible, so the signs we often see in other species, such as dogs may not be as obvious in rabbits. This doesn’t mean the condition is any less painful in rabbits though and veterinary treatment is still imperative. Normally only one leg is affected and signs your rabbit may show include:

• Holding the affected hind leg up when resting or moving.
• Dragging the affected hind leg.
• Muscle mass reduction in the affected hind leg.
• Anorexia and gastrointestinal stasis, due to the pain.
• Resentment of the affected leg being touched/moved.
• Swelling around the stifle (knee) joint.

If you notice any signs of possible cruciate ligament damage or have any concerns, you need to take your rabbit to see a rabbit savvy vet as soon as possible. If left untreated, cruciate ligament injury can lead to chronic and painful joint changes, such as osteoarthritis.

Your veterinarian will examine your rabbit, not only the hind legs, but also perform a full clinical examination. They will feel and move the knee (stifle) joint to see if it is painful or unstable. If they suspect damage to the cruciate ligament, they will want to see if your rabbit will move around in the consult room. Many rabbits will not do this, or may even hop normally when being examined, so it is a good idea to try and get a video of how your rabbit is moving at home so you can take this to show them. One of two things may be recommended:

1. Pain relief and rest to see if the problem resolves. This is likely to be for at least 6-8 weeks and in that time you are likely to need to reduce the amount of space your rabbit has, and remove any ramps and higher levels your rabbit has access to. With partial tears of the cruciate ligament, this may resolve the problem.
2. Further diagnostics, which normally include radiographs (x-rays) or referral for advanced imaging such as CT scanning, to ascertain the extent of the problem and if surgery may be required.

If your rabbit has suffered a full tear or rupture of the cruciate ligament, or rest and pain relief has not helped to resolve the clinical signs, then surgery may be required. Some rabbits may adapt with continued pain relief and some restriction in their environment, and this may be a more preferable option for an elderly rabbit or one with other health concerns, but for younger rabbits who are otherwise healthy, then surgery may be a better option. You will likely have your rabbit referred to a specialist orthopedic surgeon for this procedure and one with knowledge of rabbits and anesthetic considerations, as the surgery is not a routine procedure.

Cruciate ligament repair surgery is not routine and is likely to be expensive. If you have health insurance for your rabbit, check with the insurance company to see if this will be covered and always discuss costs with your veterinarian.

The recovery period for your rabbit will be several weeks and you will need to ensure they cannot cause any further damage to themselves during this time, so will need restricting in their environment. Careful wound checks, continuing with medication your veterinarian prescribes, and ensuring they are eating, drinking and passing urine and droppings is imperative. Physiotherapy may be recommended a few weeks after surgery and there is always the risk of post-surgical complications, but by and large rabbits recover well, and the surgery is successful.

Keeping your rabbits at an optimum bodyweight will certainly help, not only to prevent cruciate ligament tears but for their overall health and welfare, but we cannot fully prevent the condition. Always handle your rabbits carefully and ensure they cannot jump out of your arms or fall, and do not allow children to hold them. But rabbits will be rabbits and they love to run, jump and binky, which are natural behaviors and we should not discourage these.