This case report examines a herd outbreak of haemonchosis in an upstate New York 1,100-head meat sheep flock that was diagnosed by necropsy. The case report highlights the need for prompt veterinary attention in an outbreak investigation. This case report will discuss current research in treatment and management of Haemonchus contortus in North America. Finally, it will describe the multifactorial approach used to prevent Haemonchus outbreaks including pasture management, targeted selective anthelmintic use, anthelmintic choice, and genetic selection.