Traditional blanket deworming of all horses on a fixed schedule is increasingly replaced by targeted selective treatment based on individual testing. This approach has both welfare and resistance management benefits.
The shift from blanket to targeted selective treatment represents a convergence of welfare and parasite management best practice. Blanket dosing drives resistance in parasite populations, while under-treatment of high shedders causes ongoing intestinal damage and disease. Targeted testing identifies which horses need treatment and which do not — reducing unnecessary chemical exposure for low-shedding horses and ensuring high-shedding horses receive appropriate care. The welfare imperative is accurate assessment: fecal egg counts twice yearly plus an annual egg count reduction test to check anthelmintic efficacy.