06/04/2026
We highly recommend testing your cats and dogs for the MDR1 genetic defect. Easy and affordable test you can do at home.
https://prime.vetmed.wsu.edu/how-to-order/
Pets with this mutation can suffer severe side effects like tremors, blindness, and even death if administered certain types of drugs and flea/tick products. Up to 75% of some herding breeds and 4% of cats carry this mutation, making testing essential for their health.
P-glycoprotein (P-gp), also known as MDR1 (Multidrug Resistance Protein 1) is a critical cell membrane protein that acts as an active, ATP-dependent efflux pump. It recognizes and pumps a wide variety of lipophilic compounds, drugs, and toxins out of cells. In healthy bodies, P-gp acts as a protective barrier against toxins. It is highly expressed in the brain, gastrointestinal tract and in the liver and kidneys.
Approximately three of every four collies in the United States have the mutant MDR1 gene. The MDR1 mutation has also been found in Shetland sheepdogs (Shelties), Australian shepherds, old English sheepdogs, English shepherds, German shepherds, long-haired whippets, silken windhounds, and a variety of mixed-breed dogs.
More recently, Dr. Katrina Mealey at Washington State University, has discovered that up to 4% of all cats, roughly 4 million in the U.S., have the MDR1 genetic mutation. To learn more about testing and MDR1 mutation in dogs and cats, you can visit https://prime.vetmed.wsu.edu/
As an integrative veterinary practice, we like to minimize the use of drugs; however, when we do have to use drugs, it is critical to avoid any potential adverse reactions. If you need any assistance or would like to discuss this genetic defect further please give us a call at 540 338-7081.
How to order and submit your MDR1 test for dogs and cats Ordering an MDR1 genetic test is a simple way to learn whether your dog or cat has a genetic mutation that affects how certain medications are processed. Results help you and your veterinarian choose safer treatment options and avoid drugs tha...
