An Isoxazoline compound of formula (I) wherein R 1 = halogen, CF 3 , OCF 3 , CN, n = integer from 0 to 3, preferably 1, 2 or 3, R 2 = C 1 -C 3 -haloalkyl, preferably CF 3 or CF 2 Cl, T = 5- or 6-membered ring, which is optionally substituted by one or more radicals Y, Y = methyl, halomethyl, halogen, CN, NO 3 , NH 2 -C=S, or two adjacent radicals Y form together a chain, especially a three or four membered chain; Q = X-NR 3 R 4 ora 5-membered N-heteroaryl ring, which is optionally substituted by one or more radicals; X = CH 2 , CH(CH 3 ), CH(CN), CO, CS, R 3 = hydrogen, methyl, haloethyl, halopropyl, halobutyl, methoxymethyl,methoxyethyl, halomethoxymethyl, ethoxymethyl, haloethoxymethyl, propoxymethyl, ethylaminocarbonylmethyl, ethylaminocarbonylethyl, dimethoxyethyl, propynylaminocarbonylmethyl, N-phenyl-N-methyl-amino, haloethylaminocarbonylmethyl, haloethylaminocarbonylethyl, tetrahydrofuryl, methylaminocarbonylmethyl, (N,N-dimethylamino)-carbonylmethyl, propylaminocarbonylmethyl, cyclopropylaminocarbonylmethyl, propenylaminocarbonylmethyl, haloethylaminocarbonylcyclopropyl, wherein Z A = hydrogen, halogen, cyano, halomethyl (CF 3 ); R 4 = hydrogen, ethyl, methoxymethyl, halomethoxymethyl, ethoxymethyl, haloethoxymethyl, propoxymethyl, methylcarbonyl, ethylcarbonyl, propylcarbonyl, cyclopropylcarbonyl, methoxycarbonyl, methoxymethylcarbonyl, aminocarbonyl, ethylaminocarbonylmethyl, ethylaminocarbonylethyl, dimethoxyethyl, propynylaminocarbonylmethyl, haloethylaminocarbonylmethyl, cyanomethylaminocarbonylmethyl, or haloethylaminocarbonylethyl; or R 3 and R 4 together form a substituent selected from the group consisting of: and or a salt or solvate thereof, for use in the prevention or treatment of mite infestations of poultry animals, wherein an effective amount of the isoxazoline compound is administered via the drinking water in two separate dosages 7 days apart, each of them contain 50 % of the dose. R 1 = halogen, CF 3 , OCF 3 , CN, n = integer from 0 to 3, preferably 1, 2 or 3, R 2 = C 1 -C 3 -haloalkyl, preferably CF 3 or CF 2 Cl, T = 5- or 6-membered ring, which is optionally substituted by one or more radicals Y, Y = methyl, halomethyl, halogen, CN, NO 3 , NH 2 -C=S, or two adjacent radicals Y form together a chain, especially a three or four membered chain; Q = X-NR 3 R 4 ora 5-membered N-heteroaryl ring, which is optionally substituted by one or more radicals; X = CH 2 , CH(CH 3 ), CH(CN), CO, CS, R 3 = hydrogen, methyl, haloethyl, halopropyl, halobutyl, methoxymethyl,methoxyethyl, halomethoxymethyl, ethoxymethyl, haloethoxymethyl, propoxymethyl, ethylaminocarbonylmethyl, ethylaminocarbonylethyl, dimethoxyethyl, propynylaminocarbonylmethyl, N-phenyl-N-methyl-amino, haloethylaminocarbonylmethyl, haloethylaminocarbonylethyl, tetrahydrofuryl, methylaminocarbonylmethyl, (N,N-dimethylamino)-carbonylmethyl, propylaminocarbonylmethyl, cyclopropylaminocarbonylmethyl, propenylaminocarbonylmethyl, haloethylaminocarbonylcyclopropyl, wherein Z A = hydrogen, halogen, cyano, halomethyl (CF 3 ); R 4 = hydrogen, ethyl, methoxymethyl, halomethoxymethyl, ethoxymethyl, haloethoxymethyl, propoxymethyl, methylcarbonyl, ethylcarbonyl, propylcarbonyl, cyclopropylcarbonyl, methoxycarbonyl, methoxymethylcarbonyl, aminocarbonyl, ethylaminocarbonylmethyl, ethylaminocarbonylethyl, dimethoxyethyl, propynylaminocarbonylmethyl, haloethylaminocarbonylmethyl, cyanomethylaminocarbonylmethyl, or haloethylaminocarbonylethyl; or R 3 and R 4 together form a substituent selected from the group consisting of: and or a salt or solvate thereof, for use in the prevention or treatment of mite infestations of poultry animals, wherein an effective amount of the isoxazoline compound is administered via the drinking water in two separate dosages 7 days apart, each of them contain 50 % of the dose. <EOS>