Learn about Golden Retriever Muscular Dystrophy, a rare but fatal canine disease, and how GRMD is helping solve Duchenne Muscular Dystrophy in humans.
Muscular dystrophy in dogs is more often recognized in golden retrievers than in any other breed; hence the name, Golden Retriever Muscular Dystrophy. GRMD is a degenerative muscle disease associated with a deficiency of the protein dystrophin. While rare, this canine disease is severely disabling and eventually fatal.
Since GRMD presents itself by about eight weeks of age, anyone planning to breed dogs, especially golden retriever dogs, or acquire a puppy will benefit from knowing more about GRMD. No cure exists, but researchers have found promising therapies for affected dogs, therapies that may also help treat the human form of GRMD known as Duchenne Muscular Dystrophy.
Which Dogs are Affected by Golden Retriever Muscular Dystrophy?
Although not exclusive to goldens, Golden Retriever Muscular Dystrophy usually occurs in purebred dogs. But like Duchenne Muscular Dystrophy, GRMD is mostly found in males. It is carried on the X chromosome, so a male golden retriever dog only needs one parent to pass on the defective gene, unlike a female golden, who needs to inherit the gene from both parents.
That said, female golden retriever dogs can be carriers of GRMD. They can also be diagnosed with the disease; however, most females with GRMD develop a mild case of it. Fortunately, only a very small percentage of dogs – whether male or female, golden retriever or not – are affected by GRMD.
Golden Retriever Muscular Dystrophy Symptoms
The symptoms of GRMD are similar to those of Duchenne Muscular Dystrophy, but there are some differences. Look for the following in a GRMD dog:
- muscle weakness
- crouched posture
- impaired walking
- swallowing difficulty
- excessive drooling
- chewing problems
- splayed feet
- shuffling gait
- breathing difficulty
- increased exercise intolerance
Prognosis and Treatment of GRMD Canine Disease
Dogs with severe Golden Retriever Muscular Dystrophy may not live past the first few days of diagnosis, but some dogs with this canine disease can survive for several years. Often it is heart muscle disease resulting from GRMD that kills the dog. Currently, there is no proven effective treatment for GRMD.
There is some good news, though. Researchers at various institutions have been studying gene therapies for GRMD with encouraging results. A study conducted at the Stem Cell Research Institute in Milan in 2006 found that affected dogs injected with donated or genetically modified stem cells showed improvement of their symptoms. One dog could even run with a limp.
Later, researchers at the National Center of Neurology and Psychiatry in Japan had more luck with a different gene therapy. They injected affected dogs with antisense molecules, creating DNA-like patches that cover up mutant regions and allow dogs to make a functional version of dystrophin. The results? The injected dogs showed muscle function improvement and a production of dystrophin at 26 percent of normal levels.
Golden Retriever Muscular Dystrophy and Duchenne’s Disease
Of course, these studies have much larger implications. By researching muscular dystrophy in dogs, experts believe that boys with Duchenne Muscular Dystrophy can be helped using similar therapies – offering hope to Duchenne patients who often become confined to wheelchairs and die in their late teens or 20s.
Although more research and testing need to be done, promising therapies may one day provide a cure for Golden Retriever Muscular Dystrophy and, ultimately, Duchenne Muscular Dystrophy. In the meantime, genetic tests can identify golden retriever dogs and other dogs that are carriers or affected by GRMD.