Disclosed is an anti-parasitic formulation comprising (a) one or more anthelmintic compounds, wherein the compound is abamectin, ivermectin, moxidectin, doramectin or eprinomectin, (b) a co-solvent present in an amount of at least 17 per cent by weight wherein the co-solvent is an alcohol having four or more carbon atoms, selected from benzyl alcohol, ethyl benzyl alcohol, phenethyl alcohol, any aromatic monohydric alcohol, and combinations thereof (c) a castor oil present in an amount of 25 per cent by weight or less, and (d) a vegetable oil having a similar viscosity profile as compared with soya bean, sesame, or corn oil, and wherein the vegetable oil is an oil other than castor oil. The formulation can be for injection, a pour-on, or for oral administration.
