Efficacy of spinosad on the treatment of myiasis caused by Cochliomyia hominivorax (Diptera: Calliphoridae) in dogs

On average, the highest larval expulsion occurred four hours after treatment. A single spinosad treatment had an overall efficacy of 79.7% (56.7-100%). The average larval expulsion rate was 73.3% (56.7-100%), reached its maximum within 6 h post-treatment, and the average larvicidal effect was only 23.7% (0-58.3%). No animal needed a second dosage 24 h post-treatment, lesions were completely healed within 8 days post-treatment. Despite not reaching the desirable 100% efficacy, spinosad treatment is an option in managing NSW myiasis, in conjunction with mechanical removal of maggots that remain in the lesion and support treatment.