An anthelmintic compound of formula (IA-2), wherein Y is naphthyl, benzofuranyl, dihydrobenzofuranyl, quinolinyl, isoquinolinyl, tetrahydroquinolyl, tetrahydroisoquinolyl, indolyl, isoindolyl, benzothiophenyl, benzimidazolyl, or benzothiazolyl, each of which is optionally substituted by one or more of halogen, nitro, cyano, C 1-3 alkyl, C 1-3 haloalkyl, phenyl, hydroxy, C 1-3 hydroxyalkyl, amino, C 1-3 alkyl- or C 1-3 dialkylamino, C 1-3 alkoxy, C 1-3 haloalkoxy, C 1-3 alkylthio, C 1-3 haloalkylthio, C 1-3 alkylsulfinyl, C 1-3 haloalkylsulfinyl, C 1-3 alkylsulfonyl, C 1-3 haloalkylsulfonyl or SF 5; Z is phenyl optionally substituted by one or more of halogen, nitro, cyano, C 1-3 alkyl, C 1-3 haloalkyl, phenyl, hydroxy, C 1-3 hydroxyalkyl, amino, C 1-3 alkyl- or C 1-3 dialkylamino, C 1 - 3 alkoxy, C 1-3 haloalkoxy, C 1-3 alkylthio, C 1-3 haloalkylthio, C 1-3 alkylsulfinyl, C 1-3 haloalkylsulfinyl, C 1-3 alkylsulfonyl, C 1-3 haloalkylsulfonyl or SF 5; X 1 is a bond, -C -, -(CH 2) n - where n is 1 to 3, -O-CH 2 -, -NHCH 2 -, -S-CH 2 -, -S -CH 2 -, -CH 2 -S -, -S 2 -CH 2 -, and -CH 2 -S 2 -, wherein each -(CH 2) n -, -O-CH 2 -, - NHCH 2 -, -S-CH 2 -, -S -CH 2 -, -CH 2 -S -, -S 2 -CH 2 -, and -CH 2 -S 2 - are optionally substituted with oxo (=O) or one or more halogen, cyano, alkyl, haloalkyl, cycloalkyl or aryl groups; X 8 is a bond, -(CH 2) n where n is 1 to 3, -O-, -C -, -S-, -S -, -S 2 -, -NHS -, -S -NH-, -NHSO 2 -, -SO 2 NH- or -NH-, wherein each CH 2 in -(CH 2) n -, -NHS -, -S -NH-, -NHSO 2 -, -SO 2 NH- or -NH- is optionally independently substituted with one or two substituents selected from the group consisting of halogen, hydroxy, amino, C 1 - 3 alkylamino, C 1-3 dialkylamino, C 1-3 hydroxyalkyl, C 1-3 aminoalkyl, C 1-3 alkyl, C 1-3 haloalkyl and C 1-3 alkoxyalkyl; Ring A is L1, L13, L14 or L15: where R 5 and R 6 are independently hydrogen, C 1-3 alkyl or C 1-3 haloalkyl; W is O, S or an oxetane group; each R 1 is independently halogen, cyano, hydroxyl, amino, C 1-3 alkylamino, C 1-3 dialkylamino, C 1-3 alkyl or C 1-3 haloalkyl; R 2 and R 3 are independently H, halogen, C 1 -C 3 alkyl or C 1 -C 3 haloalkyl; n is 0, 1, 2 or 3; r is 0, 1, 2, 3 or 4; and wherein the compound of formula (IA-2) is not a compound selected from or Y is naphthyl, benzofuranyl, dihydrobenzofuranyl, quinolinyl, isoquinolinyl, tetrahydroquinolyl, tetrahydroisoquinolyl, indolyl, isoindolyl, benzothiophenyl, benzimidazolyl, or benzothiazolyl, each of which is optionally substituted by one or more of halogen, nitro, cyano, C 1-3 alkyl, C 1-3 haloalkyl, phenyl, hydroxy, C 1-3 hydroxyalkyl, amino, C 1-3 alkyl- or C 1-3 dialkylamino, C 1-3 alkoxy, C 1-3 haloalkoxy, C 1-3 alkylthio, C 1-3 haloalkylthio, C 1-3 alkylsulfinyl, C 1-3 haloalkylsulfinyl, C 1-3 alkylsulfonyl, C 1-3 haloalkylsulfonyl or SF 5; Z is phenyl optionally substituted by one or more of halogen, nitro, cyano, C 1-3 alkyl, C 1-3 haloalkyl, phenyl, hydroxy, C 1-3 hydroxyalkyl, amino, C 1-3 alkyl- or C 1-3 dialkylamino, C 1 - 3 alkoxy, C 1-3 haloalkoxy, C 1-3 alkylthio, C 1-3 haloalkylthio, C 1-3 alkylsulfinyl, C 1-3 haloalkylsulfinyl, C 1-3 alkylsulfonyl, C 1-3 haloalkylsulfonyl or SF 5; X 1 is a bond, -C -, -(CH 2) n - where n is 1 to 3, -O-CH 2 -, -NHCH 2 -, -S-CH 2 -, -S -CH 2 -, -CH 2 -S -, -S 2 -CH 2 -, and -CH 2 -S 2 -, wherein each -(CH 2) n -, -O-CH 2 -, - NHCH 2 -, -S-CH 2 -, -S -CH 2 -, -CH 2 -S -, -S 2 -CH 2 -, and -CH 2 -S 2 - are optionally substituted with oxo (=O) or one or more halogen, cyano, alkyl, haloalkyl, cycloalkyl or aryl groups; X 8 is a bond, -(CH 2) n where n is 1 to 3, -O-, -C -, -S-, -S -, -S 2 -, -NHS -, -S -NH-, -NHSO 2 -, -SO 2 NH- or -NH-, wherein each CH 2 in -(CH 2) n -, -NHS -, -S -NH-, -NHSO 2 -, -SO 2 NH- or -NH- is optionally independently substituted with one or two substituents selected from the group consisting of halogen, hydroxy, amino, C 1 - 3 alkylamino, C 1-3 dialkylamino, C 1-3 hydroxyalkyl, C 1-3 aminoalkyl, C 1-3 alkyl, C 1-3 haloalkyl and C 1-3 alkoxyalkyl; Ring A is L1, L13, L14 or L15: where R 5 and R 6 are independently hydrogen, C 1-3 alkyl or C 1-3 haloalkyl; W is O, S or an oxetane group; each R 1 is independently halogen, cyano, hydroxyl, amino, C 1-3 alkylamino, C 1-3 dialkylamino, C 1-3 alkyl or C 1-3 haloalkyl; R 2 and R 3 are independently H, halogen, C 1 -C 3 alkyl or C 1 -C 3 haloalkyl; n is 0, 1, 2 or 3; r is 0, 1, 2, 3 or 4; and wherein the compound of formula (IA-2) is not a compound selected from or