Cruciate ligament disease is one of the most common causes of back leg lameness in dogs seen in practice. But with early diagnosis and proper veterinary treatment, it’s a condition that can be managed.
What are the cruciate ligaments?
The cruciate ligaments are two tough, flexible bands of tissue that cross over each other, hence “cruciate” (from the latin crux, meaning cross) within the knee joint (stifle). Their role is important in stabilising the joint and preventing the bones of the leg from slipping backwards and forwards when weight is applied. We see this problem mostly in medium to large breed dogs, such as Staffordshire bull terriers, labradors and rottweilers from middle age onwards.
What is cruciate disease?
The ligament that sits slightly forward within the joint, termed the cranial ligament, is most often affected. The exact mechanisms are unknown, but it is thought that the ligament weakens and degenerates over time. In the most severe cases, the ligament can rupture completely. This can happen after trauma, such as jumping from a height. When the stabilising structure fails, the bones within the joint become mobile and unstable.
The cartilage that coats the end of the bones becomes damaged and the underlying bone gets exposed. The bare bone contains a high number of nerve endings, and is therefore painful when contacted. Pets usually express this pain through signs such as limping, toe touching or complete non-weight bearing lameness when severe. Eventually, osteoarthritis can develop as a result of this instability and cause further long term discomfort.
What do I do if my dog has back leg lameness?
If you are worried your dog is limping, struggling to weight-bear and looking uncomfortable, it is always best to seek advice from your own vet in the first instance. They will be able to examine the leg and may find clues that point towards cruciate disease. Your vet might suggest investigations with a general anaesthetic and X-rays. This will allow a proper examination of the joint while your pet is asleep, and a pain free hands-on examination of the joints’ stability. X-rays will show if there are secondary changes, such as arthritis, or other bony problems, like fractures.
My dog has cruciate disease – what are the options?
If after these investigations your vet is suspicious of cruciate disease, they will be able to discuss options with you. This may first include referral to an orthopaedic surgeon for further imaging to confirm the diagnosis, bypassing a camera into the joint via key-hole surgery to visualise the cruciate ligament. This technique is called arthroscopy (“arthro” meaning joint, and “scopy” refers to the small telescope-like camera).
Generally, cruciate disease is managed with surgery unless the lameness is very mild. In these cases, controlled exercise and pain relief can be trialled initially. This conservative approach only tends to be effective in small breed dogs; however, regardless of dog size or breed, many surgeons promote surgery as the best option, as recovery times can be quicker.
There are many different surgical techniques available for repairing a torn cruciate. The choice of the specific technique will depend on your dog’s breed, size and severity of the disease. Your vet will be able to guide you on this. All the techniques have the same aim of stabilising the joint and preventing unwanted movement whilst allowing the joint to be used normally.
Some first opinion vets in practice will be able to perform these procedures, but others will prefer to refer you to a specialist if they don’t have the appropriate equipment or skill set. Your vet will be able to advise you the best route for you.
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