Disclosed is a veterinary antiparasitic composition suitable for parenteral administration to animals comprising (a) doramectin, (b) cottonseed oil； (c) benzyl benzoate； and optionally d) one or more each of a preservative, auxiliary excipient, and fat soluble vitamin. The blend of the triglyceride with benzyl benzoate enables greater solubility of doramectin (and other macrocyclic lactones). The composition is useful for treating or preventing parasites in livestock animals.
