Katrina L. Mealey, DVM, Ph.D., DACVIM, DACVCP, and her team have identified cats with the MDR1 genetic mutation are at risk of severe adverse reactions to the active ingredient in some top-selling parasite preventatives for felines. The ingredient, eprinomectin, appears safe and effective for most cats except those with the MDR1 gene mutation. Genetic testing is the only … [Read more...]