Skip to main content

The drug checker

Check a drug against your dog's breed

Pick the breed, pick the drug, and — where the dose changes the answer — pick the dose. You'll get an MDR1 class verdict with the WSU citation and a print-for-vet card. Covers 16 drugs across 13 at-risk breeds.

Browser-only by design

Your dog's breed, the drugs you look up, and anything you type for the vet card never leave this page. We don't log, store, or sell any of it.

Independent DVM review in progress
1 · Breed2 · Drug3 · Result

Pick your dog's breed

The breed sets the baseline likelihood of the MDR1 mutation. Only a DNA test confirms an individual dog's genotype.

This is general information, not veterinary advice for your dog. It does not diagnose or prescribe. Always discuss any medication decision with your veterinarian before acting — they know your dog's full picture, including its MDR1 status if it has been tested. See our disclaimer and how we research.

One more thing the checker can't tell you: your dog's genotype

Breed sets the odds; a DNA test sets the fact. WSU classifies dogs into three genotypes, and the risk level differs for each:

  • Mutant / mutant (homozygous)

    Both copies of the gene are mutated. This is the highest-sensitivity genotype. WSU describes affected drugs as causing toxicity in homozygous dogs; reduced doses or avoidance apply most strongly here.

  • Mutant / normal (heterozygous)

    One copy is mutated and one is normal. This is an intermediate-sensitivity genotype. WSU advises that heterozygous dogs can also experience toxicity and should receive reduced doses of affected drugs.

  • Normal / normal

    Both copies are normal. A normal/normal dog does not carry the MDR1 mutation and is not at increased risk from these drugs at normal doses. A DNA test is the only way to confirm a dog is normal/normal.

Wondering whether to test? Compare the three MDR1 tests.