Researchers from American veterinary centers have identified that about 1% of domestic cats face serious complications when exposed to eprinomectin, the active ingredient found in several parasite-control medications. The finding was reported in a study published in the Journal of Veterinary Pharmacology and Therapeutics (JVPT).
Scientists explain that the risk is linked to a genetic mutation known as MDR1, which occurs in roughly one out of every hundred animals. This mutation disrupts the cat’s natural barrier that normally protects the brain from certain drugs, allowing eprinomectin to cross into the brain in some cases. When this happens, pets may suffer neurological damage and, in severe situations, death.
Cats affected by eprinomectin can exhibit a range of symptoms. Early signs often include poor coordination, hypersalivation, tremors, and partial limb weakness. In more severe instances, cats can experience dilated pupils, seizures, or even coma. There are also reports of cats being unable to retract their tongues for extended periods after dosing. The variability in symptoms makes early detection challenging and underscores the need for veterinary oversight when selecting antiparasitic therapies.
Veterinarians emphasize that the most reliable method to determine if a cat carries the MDR1 mutation is genetic testing. This test can guide safer treatment choices and help avoid drugs that may pose a higher risk to MDR1-positive cats. Pet owners are encouraged to discuss the option of genetic screening with their veterinarian, particularly for breeds or lines with known exposure to MDR1-related concerns.
In light of these findings, practitioners are advised to review every feline patient’s medication plan in collaboration with genetic considerations in mind. When eprinomectin or related compounds are contemplated, alternative medications or adjusted dosing strategies should be considered for cats with the MDR1 mutation. The overarching goal is to balance effective parasite control with the safety and well-being of each individual animal.