Canine degenerative myelopathy (also known as degenerative radiculomyelopathy-CDRM) is a progressive disease of the spinal cord in older dogs.  The disease has an insidious onset typically between 7 & 14 years of age.  The mutated gene has been found in more than 40 breeds including collies

Luckily it is not thought to be a painful condition and mentally the dogs remain normal.   It starts with dragging of toes, uneven nail growth in the back feet and ataxia leading eventually to paralysis in the hind legs.  

There is no cure and numbers of Smooth Collies affected have been small.  

Any dog can get DM. Being homozygous for the gene makes it more likely that a dog will get clinical DM, but a clear or carrier does not mean they will not get DM, clear and carrier dogs have been confirmed with DM on autopsy, DM cannot be diagnosed without an autopsy. DM is a disease that looks like other diseases, and many other diseases can look like DM. DM is a specific disorder, it is not a back problem, where a dog loses control of its back legs, limps or has progressive paralysis. It is not the only nerve disorder and it is not the only thing that makes dogs lose rear function. Dogs can “go down” because of disc disease, a whole load of muscle diseases, other nervous disorders, vestibular issues, a huge range of injuries, and even the simple muscle atrophy of old age. Any one of these can mimic DM.

Exercise and other forms of physical therapy are very important to help delay the onset of disuse muscle atrophy associated with DM and to help affected dogs maintain mobility and strength in their pelvic limbs. This commonly involves what are called “range of motion” exercises (passive stretching and flexing of the rear legs by hand in a regular pattern). Activity seems to slow the progression of the disease, and as a result with regular physical therapy affected dogs are able to maintain strength, balance and the ability to walk for a longer period of time. Recently, hydrotherapy also has proven to be beneficial for dogs with this disease. This involves swimming exercises, underwater treadmill use and other techniques that help the dog exercise and use its muscles.

A viable management option for dogs that have lost mobility in their pelvic limbs is the use of a wheel cart – essentially, a wheelchair for dogs. As long as the dog is able to use its front legs normally, a wheel cart will keep it comfortable and mobile. Once the front limbs are severely affected, a wheel cart cannot be used. Your veterinarian can help you find a wheel cart suited to your particular dog.

No drug has proven effective in slowing or stopping the progression of canine DM. Vitamins and omega-3 fatty acid supplementation have been advocated as potential therapies but are not yet proven. Vitamin E, vitamin B complex and vitamin C are under investigation as possible useful supplements for managing this disease. Their efficacy also is unknown. Other chemical therapies are being studied, including administration of aminocaproic acid and the potent antioxidant, acetylcysteine. These experimental treatments have some adverse side effects, are expensive and may require long-term use. Still, if no other treatment protocol helps a particular dog, these unproven “treatments” may be considered. Of course, a veterinarian is the only one able to assess and decide upon the right treatment regimen for an affected dog. The suspected diagnosis of degenerative myelopathy is based on clinical signs, breed, and age and supported by the absence of other clinical diseases.