Tilmicosin is a macrolide antibiotic. It is used in veterinary medicine for the treatment of bovine respiratory disease and enzootic pneumonia caused by Mannheimia (Pasteurella) haemolytica in sheep.[2] In humans, Tilmicosin causes fatal cardiotoxic effects at amounts greater than 1 milliliter when injected, something most commonly seen in veterinary personnel and farmers. [3]