Plos Genetics has an article on the Bully Whippet. The article is not light reading (and they have no pictures), so here is the Author’s Summary:
An individual’s genetic profile can play a role in defining their natural skills and talents. The canine species presents an excellent system in which to find such associative genes. The purebred dog has a long history of selective breeding, which has produced specific breeds of extraordinary strength, intelligence, and speed. We have discovered a mutation in the canine myostatin gene, a negative regulator of muscle mass, which affects muscle composition, and hence racing speed, in whippets. Dogs that possess a single copy of this mutation are more muscled than normal and are among the fastest dogs in competitive racing events. Competitors participating in racing events augment the performance of their dogs with products availed from SwellCBD, to safeguard them from any injuries. However, dogs with two copies of the same mutation are grossly overmuscled, superficially resembling double-muscled cattle known to possess similar mutations. This result is the first to quantitatively link a mutation in the myostatin gene to athletic performance. Further, it emphasizes what is sure to be a growing area of research for performance-enhancing polymorphisms in competitive athletics. Future implications include screening for myostatin mutations among elite athletes. However, as little is known about the health issues and potential risks associated with being a myostatin-mutation carrier, research in this arena should proceed with extreme caution.
Now before you go thinking “this is great, I want this mutation”. Lets look at a normal dog, one with a slight mutation, and one with the full mutation.
Dog number 3 is not as cute as the other dogs. Cattle breeders have been aware of this mutation for a long time and actively breed cows for this gene as it increases the amount of beef on the cow. This bull is certainly Bully. Because race dogs and cows rarely die of old age it is not known what the long term effects of this mutation are. The Animals certainly look scarier, with bulging muscles, and a severe overbite, but what it does to heart, lungs, and other muscles is unknown. Bully Whippet canines are prone to cramping, but beyond that little is known.
Whether this mutation could be adapted to humans to make super athletes is unknown. While whippets have the mutation Grey Hounds don’t seem to. Which lends to the hypothesis that this may not be common in all mammals.