Provided are veterinary anthelmintic formulations comprising at least one macrocyclic lactone, levamisole and dimethyl sulfoxide (DMSO). The formulations may further comprise an anthelmintic benzimidazole . One of the preferred embodiments is a veterinary formulation comprising at least one macrocyclic lactone at 0.5-1% by weight, levamisole at 10-20% calculated by weight of levamisole base and DMSO at 50-80% by weight . Further provided is a method of treating internal and/or external parasites in a non-human animal using the formulations and the use of the formulations in the manufacture of a medicament for the treatment of internal and/or external parasites in an animal.
