X-linked muscular dystrophy

What is ... ?: 

This inherited disease is caused by the lack of a single specific protein (dystrophin) which is normally found in muscle fibres. This disease is similar to Duchenne muscular dystrophy in humans. The first sign is usually difficulty in swallowing, which is seen as early as 6-8 weeks of age. The clinical signs will progress from poor suckling to generalized muscle weakness and exercise intolerance to muscle withering (atrophy), curvature of the spine, muscle contractures, and heart problems.

How is ... inherited?: 

The trait is sex-linked. This means that it is carried by females (clinically unaffected) whose male offspring will have a 50 per cent chance of developing the disease.

What does ... mean to your dog & you?: 

Unfortunately this is a severe, debilitating, progressive disease. It may progress rapidly or more slowly, and your dog will gradually become weaker and more debilitated. There is no specific treatment or cure.

How is ... diagnosed?: 

Your veterinarian will suspect this disease if your young pup exhibits a combination of the following clinical signs: generalized muscle weakness and atrophy, exercise intolerance, abnormal gait, excessive drooling, abnormal spinal curvature. This diagnosis can be confirmed with blood tests (to look for elevated muscle enzymes), muscle biopsy, electromyography, and a neurological exam.

How is ... treated?: 

There is no cure or specific treatment for this disease. Some of the clinical signs may be treated with drugs, and physiotherapy may also be helpful.

Breeding advice: 

Affected dogs should not be bred. The mother of any affected dog is a carrier of the condition and should not be used for breeding purposes.


Kornegay JN. 1995. Disorders of the skeletal muscles. In EJ Ettinger and EC Feldman (eds) Textbook of Veterinary Internal Medicine, pp.727-736. WB Saunders Co., Toronto.

Ackerman L. 1999. The Genetic Connection: A Guide to Health Problems in Purebred Dogs pp.121-122. AAHA Press,Lakewood, Colorado.

What breeds are affected by ... ?