Disclosed herein are isoxazoline compounds of formula (I), wherein the substituents are as defined within the specification, processes for their preparation, compositions comprising said compounds and uses thereof. Said compounds are useful in the control of ectoparasites, especially insects and acari, on non-human animals, especially productive livestock and domestic animals. Examples of superficially preferred compounds include: 5-[5-(3,5-dichloro-phenyl)-5-trifluoromethyl-4,5-dihydro-isoxazol-3-yl]-3-methyl-thiophene-2-carboxylic acid [(2,2,2-trifluoro-ethylcarbamoyl)-methyl]-amide； or 5-[5-(3,5-dichloro-phenyl)-5-trifluoromethyl-4,5-dihydro-isoxazol-3-yl]-3-methyl-thiophene-2-carboxylic acid (4-trifluoromethyl-thiazol-2-yl)-amide； or 5-[5-(3,5-dichloro-phenyl)-5-trifluoromethyl-4,5-dihydro-isoxazol-3-yl]-3-methyl-thiophene-2-carboxylic acid ethylcarbamoylmethyl-amide； or 5-[5-(3,5-bis-trifluoromethyl-phenyl)-5-trifluoromethyl-4,5-dihydro-isoxazol-3-yl]-3-methylthiophene-2-carboxylic acid [(2,2,2-trifluoro-ethylcarbamoyl)-methyl]-amide； or 5-[5-(3,4,5-trichloro-phenyl)-5-trifluoromethyl-4,5-dihydro-isoxazol-3-yl]-3-methyl-thiophene-2-carboxylic acid [(2,2,2-trifluoro-ethylcarbamoyl)-methyl]-amide； or 5-[5-(3,5-dichloro-4-fluoro-phenyl)-5-trifluoromethyl-4,5-dihydro-isoxazol-3-yl]-3-methylthiophene-2-carboxylic acid [(2,2,2-trifluoro-ethylcarbamoyl)-methyl]-amide.
