Multidrug Resistance Mutation (ABCB1 or MDR1)

An ABCB1 gene variant can increase sensitivity to certain medicines. Testing and awareness of breed risk help guide safer prescribing.

Editorial overview based on the linked VCA resource; this is not the complete original handout. Prepared 2026-10-03; not veterinarian-reviewed. Diagnosis and treatment, including medication choice and dose, require veterinary guidance.