The Shetland Sheepdog, often known as the Sheltie, is a breed of herding dog that originated in the Shetland Islands of Scotland. The original name was Shetland Collie, but this caused controversy among the Rough Collie breeders of the time, so the breed's name was formally changed. This breed was formally recognized by The Kennel Club (UK) in 1909. According to the College of Veterinary Medicine at Washington State University, the Shetland Sheepdog, and many other herding breeds, have a risk of being born with a MDR1 Gene Mutation, with about 15 percent of individuals affected. Cross-breeds are also affected. Dogs carrying Mdr1-1 share a common ancestor that experienced remarkable evolutionary success, having contributed genetically to at least nine distinct breeds of dog. Due to this genetic mutation, affected dogs may exhibit sensitivity or adverse reactions to many drugs, including acepromazine, butorphanol, doxorubicin, erythromycin, ivermectin, loperamide, milbemycin, moxidectin, rifampin, selamectin, vinblastine, and vincristine.