2001-Fri Mar 24 15:53:50 EDT 2017
Vetstreet. All rights reserved. Powered by Brightspot.
Vetstreet does not provide medical advice, diagnosis, or treatment. See Additional Information ›
Myotonia is a condition that results in constant contraction or delayed relaxation of voluntary muscles. It may be congenital, meaning that it is present before or at birth, or it can be an acquired condition later in life. A handful of dog breeds are known to be affected, and the condition is rare in cats. Pets with myotonia have a stiff gait and trouble getting up. They might have difficulty swallowing. Although there is no specific treatment for the disease, there is a drug that can reduce some signs in pets, but many pets with this condition are euthanized.
The congenital form of this disease, more aptly termed myotonia congenita, is caused by a defect in the muscle membrane. Chloride channels within the membrane (which allow complex electrical impulses to pass from nerves to muscles) do not function properly, resulting in constant contraction or delayed relaxation of voluntary muscles (like that of most of the skeletal system).
In some cases, myotonia has been found to be acquired; that is, dogs with certain conditions may also experience chloride channel disturbances by virtue of their primary disease. Cushing’s disease has been associated with myotonia in dogs, and some infectious or immune-mediated conditions may also result in similar signs.
Dogs with myotonia exhibit a stiff gait, have trouble rising, and may have an abnormal bark and difficulty swallowing. Young dogs start to show signs as early as a few weeks old, although the acquired form may occur at any age.
A DNA test pioneered by the University of Pennsylvania is currently available to screen for both carriers and diseased Miniature Schnauzers. Muscle biopsy and electromyography (or EMG, a study of electrical impulses in the muscles) have also been shown to be helpful in diagnosing the problem.
Chow Chows and Miniature Schnauzers have been documented as affected breeds.
Procainamide, a drug usually used to treat heart arrhythmias, has been found to reduce the signs in many affected dogs. Apart from this approach, nothing is known to be effective, including (to date) treatment of the underlying disease in those who have acquired (noncongenital) forms of myotonia. Few dogs will ever be free of symptoms altogether and many are euthanized.
Prevention of congenital myotonia is achieved primarily through testing of affected breeds and removing carriers or affected patients from the breeding pool through spay and neuter. A campaign is currently underway by the University of Pennsylvania to test all Miniature Schnauzers intended for breeding to completely eliminate the problem in this breed.
This article has been reviewed by a Veterinarian.
Like this article? Have a point of view to share? Let us know!
Bartonella is a type bacteria that can be transmitted to cats, dogs and humans from exposure to infected fleas and…
Want to give your pup yummy, low-calorie treats? We’ve got the skinny on which foods are OK to feed him.
Not sure about food puzzles? Our veterinarian reveals why the payoff for your pet is well worth any extra work.
With these simple dental care tips, you can help keep your canine’s adorable smile shiny and healthy for life.
The friendly and inquisitive LaPerm has an easy-care coat that comes in a variety of colors and patterns.
Check out our collection of more than 250 videos about pet training, animal behavior, dog and cat breeds and more.
Wonder which dog or cat best fits your lifestyle? Our new tool will narrow down more than 300 breeds for you.
Thank you for subscribing.