Bully Whippet Syndrome


A disease of muscle growth, affected dogs are heavily muscled and quite athletic. It arises from a mutation in the MSTN gene, which codes for myostatin, a protein with inhibitory effects on muscle growth. Mutations in myostatin have been reported in numerous species and breeds including Belgian Blue cattle, Texel sheep, and even humans! Dogs deficient in myostatin mirror other animal models: they are the natural bodybuilders of the animal world.

  • Signs and symptoms

    The double muscling is obvious when comparing an affected dog to a typical Whippet. Muscle cramping has been reported.

    Signs develop in juvenile dogs.

    Uncover health risks with Embark

    Embark Breed + Health Test

    Original price:


    Sale price:



    Embark for Breeders Dog DNA Test

    $129 - $159


  • Diagnosis

    Genetic testing and clinical signs can be used to diagnose this condition.

  • Treatment

    There is no treatment necessary for this condition.

  • What to do if your dog is at risk


    • Be aware of this condition if choosing to breed or show your Whippet.

  • Genetic Information

    This mutation was first described in the Whippet.

    Dogs carrying two copies of the MSTN mutation are heavily muscled and, due to breed standards, are precluded from whippet races. However, carriers for the MSTN mutation are less heavily muscled and are known as "bully whippets." They meet breed standards and are often eligible to race, and can be argued to have a significant athletic advantage against their normally muscled competitors.

    Gene names:

    MSTN ‐ chr37

    Inheritance type:


  • Breeds affected

    This health condition affects the following breeds

Learn about your dog’s unique genetic health

Dog owners

Breed identification, health and trait insights, personalized care recommendations, and the world’s first canine relative finder—all in one leading dog DNA test.

Learn about the report for dog owners
Shop the test
Breeding programs

Embark’s test for breeding programs is one comprehensive DNA test designed with your needs in mind.

Learn about the report for breeders
Shop the test