Disclosed is method for protecting a non-human mammal such as livestock, a canine (including dogs), a feline (including cats) from fleas, by administered orally or parenterally a compound of Formula 1, which is fluralaner (4-[5-(3,5-dichlorophenyl)-5-trifluoromethyl-4,5-dihydroisoxazol-3-yl]-2-methyl-N-[(N-(2,2,2-trifluoroethyl)carbamoyl)methyl]benzamide / 4-[5-(3,5-dichlorophenyl)-5-trifluoromethyl-4,5-dihydroisoxazol-3-yl]-2-methyl-N-[N-(2,2,2-trifluoroethyl)carbamoyl methyl]benzoic acid amide / 4-[5-(3,5-dichlorophenyl)-4,5-dihydro-5-(trifluoromethyl)-3-isoxazolyl]-2-methyl-N-[2-oxo-2-[(2,2,2-trifluoroethyl)amino]ethyl]benzamide), an N-oxide or a salt thereof. Preferably, the compound is administered such that the mammal is protected for 24 hours after oral, parenteral administration or injection. It is also disclosed that fluralaner is to be administered orally or parenterally about daily to yearly, about weekly to about once every six months, and preferably monthly.
