Parasite management – Resistance is futile…. Parasite management is a concern for anyone raising livestock. Coming from a horse and cattle background, frequent treatment for internal parasites was the norm for me. We commonly dewormed our cows several times a year. The horses were dewormed fall and spring. I don’t remember anyone ever talking about resistance to these drugs being an issue, although in cattle it is now becoming one. The first year we had our sheep, when I consulted my veterinarian about what dewormer to administer, he cautioned me about the potential for drug resistance to form without careful …