Disclosed herein is the use of 4-[5-(3,5-Dichlorophenyl)-5-trifluoromethyl-4,5-dihydroisoxazol-3-yl]-2-methyle=-N-[N-2,2,2-trifluoroethyl)carboamoylmethyl]benzoic acid amide (an isoxazoline compound of formula (11-1) or (17-1)) in the manufacture of a medicament for the treatment of ectoparasite infestations or parasitoses of a non-human animal, wherein a dose of the isoxazoline of a salt of the isoxazoline, or a solvate of the isoxazoline or salt is administered topically at a monthly or longer frequency.
