Muscular Hypertrophy (Double Muscling)

General Information: Muscular Hypertrophy (Double Muscling) is an inherited disorder in dogs where a mutation in the myostatin (MSTN) gene leads to increased muscle mass. Dogs with at least one copy of the mutated gene are predisposed to this condition, which can manifest at any age. Symptoms include visibly larger muscles, especially in the shoulders, thighs, and hindquarters, enhanced strength, and sometimes reduced flexibility. While this condition can result in impressive physical development, it may also lead to health issues such as joint problems, reduced stamina, and potential difficulties in giving birth due to increased muscle mass. Despite the potential for enhanced physical abilities, affected dogs may require specialized care to manage and mitigate any associated health concerns.

How to Read Your Dog's Test Results for this Genetic Variant:

Two Variants Detected: Dog Likely Affected

One Variant Detected: Dog Likely Affected

No Variants Detected: No Effect

Gene / Testing Information: Genetic testing of the MSTN gene can determine if a dog is a carrier of Muscular Hypertrophy (Double Muscling). This condition is inherited in an autosomal dominant manner, meaning that dogs must inherit at least one copies of the mutated gene to develop the condition. Carrier dogs, possessing only one copy of the mutation do show symptoms and will pass the gene to 50% of their offspring. When two carriers are bred, each pup has a 75% chance of developing the condition and a 50% chance of being a carrier. Reliable genetic testing is crucial for informed breeding practices to manage and potentially reduce the incidence of this trait in breeding lines. Breeding two carriers together is not recommended to avoid producing affected pups. Dogs that are not carriers have no increased risk of having affected offspring.