Common Symptoms
Golden Retriever muscular dystrophy is an inherited disease affecting Golden Retrievers. Affected dogs are unable to produce adequate amounts of a protein important for muscle contraction and relaxation. By 10 weeks of age affected puppies are noticeably smaller than littermates shortly after birth due to decreased growth associated with the inability to nurse. Affected dogs often need to be hand or bottle fed to prevent starvation. Beginning around 6 weeks of age, dogs begin to develop a progressively abnormal gait, muscle weakness, excessive drooling, muscle Atrophy of the head and trunk, abnormal extension or flexion of joints and a “roach backed” appearance in the lumbar spine that eventually progresses to a concave flexion. Affected dogs may also suffer from aspiration pneumonia and cardiac disease. The prognosis is related to disease severity with some dogs dying soon after birth due to disease complications and others surviving for years with only mild symptoms.
Breed-Specific Information for the Golden Retriever
The Mutation of the DMD gene associated with Golden Retriever muscular dystrophy has been identified in Golden Retrievers, although its overall frequency in this breed is unknown.
Testing Tips
Genetic testing of the DMD gene in Golden Retrievers will reliably determine whether a dog is a genetic Carrier of Golden Retriever muscular dystrophy. Golden Retriever muscular dystrophy is inherited in an X-Linked Recessive manner in dogs meaning that female dogs with one copy of the Mutation are carriers and that affected female dogs must receive two copies of the mutated gene (one from each parent) to develop the disease while male dogs only require one copy of the mutated gene from the mother in order to develop disease. Therefore, male dogs more commonly present with symptoms of the disease. Each male pup that is born to a female dog known to be a carrier of Golden Retriever muscular dystrophy has a 50% chance of inheriting the disease. Female dogs that are not carriers of this mutation have no increased risk of having affected pups. Reliable genetic testing is important for determining breeding practices. In order to eliminate this mutation from breeding lines and to avoid the potential of producing affected pups, breeding of known carriers is not recommended. Golden Retrievers that are not carriers of the mutation have no increased risk of having affected pups.
There may be other causes of this condition in dogs and a normal result does not exclude a different mutation in this gene or any other gene that may result in a similar genetic disease or trait.
References
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Brinkmeyer-Langford C, Kornegay JN. Comparative genomics of X-linked muscular dystrophies: The Golden Retriever Model. Curr Genomics. 2013 Aug;14(5):330-42. doi: 10.2174/13892029113149990004.
[PubMed: 24403852]
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Kornegay JN, Bogan JR, Bogan DJ, Childers MK, Li J, Nghiem P, Detwiler DA, Larsen CA, Grange RW, Bhavaraju-Sanka RK, Tou S, Keene BP, Howard JF, Jr., Wang J, Fan Z, Schatzberg SJ, Styner MA, Flanigan KM, Xiao X, Hoffman EP. Canine models of Duchenne muscular dystrophy and their use in therapeutic strategies. Mamm Genome. 2012 Feb;23(1-2):85-108. doi: 10.1007/s00335-011-9382-y. Epub 2012 Jan 5. Review.
[PubMed: 22218699]
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Sharp NJ, Kornegay JN, Van Camp SD, Herbstreith MH, Secore SL, Kettle S, Hung WY, Constantinou CD, Dykstra MJ, Roses AD, Bartlett RJ. An error in dystrophin mRNA processing in golden retriever muscular dystrophy, an animal homologue of Duchenne muscular dystrophy. Genomics. 1992 May;13(1):115-21.
[PubMed: 1577476]
