This case study discusses an eight month old Wensleydale ram lamb who presented for lethargy, bruxism, and respiratory distress. On examination, the sheep was febrile and tachypneic with marked edema on his ventral head and neck and had very pale mucous membranes. Initial bloodwork revealed a severe regenerative anemia. A Haemonchus contortus infection was suspected and while a fecal sample was submitted for analysis, the sheep was treated immediately and intensively for his anemia and parasite burden. Supportive therapy and hospitalization continued until a follow-up fecal exam eight days later showed the persistence of parasite eggs and the lamb was treated with a different anthelmintic. This paper reveals the details of the case findings and management and also discusses the strategies to control parasites in the face of growing chemical anthelmintic failure.