Multidrug Resistance


Turnaround: 10-15 business days

Not sure how the process works? Have a read of our Frequently Asked Questions.

Our DNA test for Multidrug Resistance is ideal for breeders and owners who want the reassurance of genetic health testing.

The guideline turnaround time for single tests is approximately 10-12 working days after the swab arrives at the lab. 

If you need more than two tests it is often more cost-effective to order the relevant breed package.


Multidrug Resistance 1 (MDR1), or Invermectin Sensitivity, causes reactions to certain classes of drug. An inability to metabolize these drugs can cause severe reactions or death even at low doses, and so vets should be made aware of this disorder.

An autosomal recessive condition caused by a mutation in the ABCB1 gene.


This test is also included in the following bbreed packages:

  • Australian Shepherd
  • Border Collie
  • German Shepherd
  • Old English Sheepdog
  • Rough Collie
  • Sheepadoodle
  • Shetland Sheepdog
  • Smooth Collie


Scientific references:

Mealey KL, Bentjen SA, Gay JM, Cantor GH. Ivermectin sensitivity in collies is associated with a deletion mutation of the mdr1 gene. Pharmacogenetics. 2001 Nov;11(8):727-33