Flea & Tick
With the ever growing threat of lyme disease and the discovery of very tiny black legged deer tick on our child the other day, we’ve decided to up our game on the combat towards the unfortunate arachnids, but what about MDR1? Well first the facts;
What is MDR1?
MDR1 or Multi-drug Resistance 1 is a genetic mutation found in many of the herding breeds, some sighthound breeds, and many mixed dogs. This mutation can have a significant impact on drug sensitivity. The MDR1 gene is responsible for production of a protein called P-glycoprotein. The P-glycoprotein molecule is a drug transport pump that plays an important role in limiting drug absorption and distribution (particularly to the brain) and enhancing the excretion/ elimination of many drugs used in dogs. As a result, dogs with the MDR1-mutation may have severe adverse reactions to some common drugs. Multi-drug Sensitivity – MDR1- Retrieved from
If my dog is only a carrier is he still affected?
Some testing labs refer to having one copy of MDR1 or other genes as having “carrier” status. This is only accurate if the gene mutation in question is recessive. That is not the case with MDR1, which is incompletely dominant. Dogs with one copy are affected, though to a lesser degree. They will react to every drug on the list if the dosage is high enough. ASHGI Rev. March 2013 MDR1 FAQ’s – Retrieved from http://www.ashgi.org/home-page/genetics-info/faq/mdr1-faqs
If my dog tests negative for MDR1 is she affected?
Dogs that do not carry an MDR1 mutation may safely receive the listed drugs. ASHGI Rev. March 2013 MDR1 FAQ’s – Retrieved from http://www.ashgi.org/home-page/genetics-info/faq/mdr1-faqs
At Coyote Creek, we treat all our dogs as if they test positive regardless of the fact that many of them do not carry even a single copy. Better safe than sorry, in our opinions.
Is there a list to reference regarding drugs known to cause a problem in herding dogs?
Yes absolutely there is! You can find it by following the link provided: MDR1 Printable List
So what products can I actually use anyway?
This is a question best answered by your veterinarian, all decisions should be discussed with a professional. At Coyote Creek, we have decided to go with Frontline Plus for the time being. We also proudly sport Atlantick spray on our dogs and ourselves.
You can read up on Atlantic here; https://www.atlantick.ca
We currently are using Frontline Plus, but only on an as necessary basis.