Congenital Myasthenic Syndrome (Golden Retriever Type)

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Common Symptoms

Congenital Myasthenic Syndrome (Golden Retriever Type) is an inherited Neuromuscular Disease affecting Golden Retrievers. Affected dogs typically present around 6-7 weeks of age with exercise-induced weakness leading to collapse. During these episodes, dogs have a short-strided gait that progressively worsens until they collapse. Weakness resolves after rest and dogs are clinically normal between episodes. Dogs develop resistance to treatments used for a similar, acquired form of the disease known as myasthenia gravis, and are often humanely euthanized due to disease severity and poor quality of life.

Testing Tips

Genetic testing of the COLQ gene will reliably determine whether a dog is a genetic Carrier of Congenital Myasthenic Syndrome (Golden Retriever Type). This disease is inherited in an Autosomal Recessive manner in dogs meaning that they must receive two copies of the mutated gene (one from each parent) to develop the disease. In general, carrier dogs do not have features of the disease but when bred with another carrier of the same Mutation, there is a risk of having affected pups. Each pup that is born to this pairing has a 25% chance of inheriting the disease and a 50% chance of inheriting one copy and being a carrier of the COLQ gene mutation. 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 to each other is not recommended. Dogs 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.


  • Tsai KL, Vernau KM, Winger K, et al. Congenital myasthenic syndrome in Golden Retrievers is associated with a novel COLQ mutation. J Vet Intern Med. 2020;34:258–265.