Multidrug Sensitivity in Dogs
The Veterinary Clinical Pharmacology Laboratory will be
closed December 23rd, through December 27th, 2013.
MDR1 genotyping services will resume December 30, 2013. We
will be closed January 1st, 2014.
questions regarding MDR1-related medical emergencies will be
answered during this time period but all other
requests/questions will be addressed on or after December 30th,
We apologize for any inconvenience these
closures may cause.
Many herding breed dogs have a genetic predisposition to adverse drug
reactions involving over a dozen different drugs. The most serious adverse drug
reactions involve several antiparasitic agents (ivermectin, milbemycin and
related drugs), the antidiarrheal agent loperamide (Imodium), and several
anticancer drugs (vincristine, doxorubicin, others). These drug sensitivities
result from a mutation in the multidrug resistance gene (MDR1 gene). At
Washington State University's College of Veterinary Medicine you can test your
dog for multidrug sensitivity and prevent serious adverse drug reactions. We can
work with your dog’s veterinarian to find appropriate drug doses or alternative
drugs for your dog based on results of MDR1 testing.
The Partnership for Preventive Healthcare, is an initiative jointly sponsored by
the American Animal Hospital Association and the American Veterinary Medical
Association. Together the two associations offer a set of Canine and Feline
Preventive Healthcare Guidelines. One of the important recommendations is that
dog owners use genetic testing—like the MDR1 test —as part of an overall
healthcare plan for their pets.
Test Your Dog
Video showing how to collect samples from your dog
The discovery of the mutation of the multi-drug resistant gene (mdr1),
establishment of testing procedures, and development of all reagents was
made by Washington State University. It is also a patent protected
diagnostic test offered exclusively by Washington State University that
has not been licensed to any other entity in the United States. It is
licensed in Australia and Europe. Any unlicensed use or marketing of the
patented test is a violation of federal statute under 35 u.s.c. 271.
Unless testing is conducted by Washington State University's Veterinary
Clinical Pharmacology Laboratory, Washington State University cannot
control quality and accuracy and consumers may risk receiving inaccurate
Most Commonly Affected Breeds
Australian Shepherd (Mini)
Click here for a complete list