VetGen - The leader in veterinary genetic disease research and genetic disease detection services for purebred animals

Breeds Serviced

  • Australian Shepherd
  • Bearded Collie
  • Border Collie
  • Collie
  • English Shepherd
  • German Shepherd
  • Miniature American Shepherd
  • miniature Australian Shepherd
  • Olde English Bulldog
  • Old English Sheepdog
  • Shetland Sheepdog
  • Silken Windhound
  • Whippet
  • White Swiss Shepherd

MDR1 - Multidrug Resistance 1

Multidrug resistance is an inherited condition, originally known as Ivermectin sensitivity. It is primarily found in the Collies and allied breeds. The condition actually affects the ability of the animal to normally process a number of commonly used drugs, and can lead to a variety of neurologic symptoms. The condition is inherited as an incompletely dominant autosomal trait. This means it is possible for “carriers” or dogs with a single copy of the mutation to show symptoms, but most often, it is dogs with two copies (affected) that are at risk of adverse drug reactions. Your veterinarian should be made aware of any dogs that are not clear.

Acepromazine (tranquilizer), butorphanol (pain control), doramectin, doxorubicin, emodepside, erythromycin, ivermectin (found in heartworm medications), loperamide(anti-diarrheal agent), milbemycin, moxidectin, paclitaxel, rifampin, selamectin, vinblastine (anti-cancer agent), vincristine and vinorelbine