http://actionnooz.com/ethics/meet-wendy-the-bully-whippet-superdog-double-muscle/
"Wendy has a muscular mutation that results in extremely bulked muscles. This condition is known as myostatin related muscle hypertrophy, or more simply, double-muscle.
Through a two base-pair deletion in the whippet myostatin gene (MSTN), and a subsequent rejection of myostatin by muscle cells, Wendy has very fast muscle growth and repair, at levels where she has quickly grown up to hulking proportions.
The increased muscle mass, along with metabolism and extremely low levels of body fats, can translate to impressive super-feats, including marked increases in speed, agility and power.
As documented by quantitative assay, whippets with this mutation seem to be consistently superior in racing events to their “wild-type” counterparts.
As you may already be thinking, a dog with genetically documented and known super-speed? Clearly this does and will raise major ethical concern in terms of dog breeding, as it may also within humans as we continue to learn and master the workings of our own genome.
Double muscle is still a condition under recent scientific scrutiny and testing, only having been adequately surveyed in humans since the year 2000."
