In the simplest sense, muscular dystrophy is defined as any degenerative muscular disorder that can be attributed to faulty “nutrition” of muscle cells, fibers and tissues. The muscular dystrophies in domestic dogs are a group of somewhat rare, progressive and degenerative hereditary disorders that involve an abnormality in, or a deficiency of, certain proteins that are critical to coordinated movement, among other things. These are called cytoskeletal proteins. There are a number of different types of muscular dystrophy in mammals. In veterinary medicine, the types seen most frequently are canine X-Linked muscular dystrophy (CXMD), Becker’s muscular dystrophy (BMD) and autosomal recessive muscular dystrophy (ARMD). ARMD is especially prevalent in Labrador Retrievers and was formerly called type 2 muscle fiber deficiency. BMD is a fairly mild form of muscular dystrophy that has been reported in the Japanese Spitz. Canine X-linked muscular dystrophy, which is strikingly similar to Duchenne muscular dystrophy in people, has also been called Golden Retriever muscular dystrophy (GRMD) because of its prevalence among male Golden Retrievers. It is probably the most widely seen form of the disease seen in veterinary practices.
Canine X-linked muscular dystrophy (CXMD) is a genetic disorder that is caused by an abnormality in a particular location on a particular gene located on the X chromosome. In this disease, certain molecules called cytoskeletal proteins are either absent or are present in insufficient amounts. The cytoskeletal protein most commonly deficient in dogs with CXMD is dystrophin. This is the same protein that is lacking in humans who have Duchenne muscular dystrophy. The genetic abnormality
It is difficult to speculate about how a dog that has a severe muscle disorder is affected by the disease. Many puppies born with canine X-linked muscular dystrophy (CXMD) are weak and die shortly after birth. If an affected dog lives, certainly its inability to eat and swallow normally must cause it some degree of frustration or distress. Moreover, aspiration pneumonia is unpleasant under any circumstances, with its associated coughing, sore throat, difficulty breathing and
Because canine X-linked muscular dystrophy (CXMD) almost always is obvious at an early age, it usually can be diagnosed without much difficulty. Of course, any “sick” puppy brought to a veterinarian will have a thorough physical examination. It probably will also have a urinalysis and routine blood work, including a complete blood count and a serum biochemistry profile. The results of the chemistry profile in dogs with CXMD will show dramatically elevated levels of creatine
Unfortunately, there are no proven treatments for dogs suffering from X-linked muscular dystrophy (CXMD). One of the key goals of managing dogs with this disease is to do whatever is possible to prevent them from developing pneumonia. Aspiration pneumonia often occurs in dogs with CXMD as a result of their inability to chew and swallow properly, and also because of the abnormal functioning of the muscles of their esophagus and diaphragm, which promotes regurgitation. If