This invention relates to a method of controlling or preventing infestations of ectoparasites, preferably hematophageous ectoparasites, on an animal by administering to the animal a composition comprising an parasiticidally effective amount of a compound of Formula 1, or an N-oxide, or a pharmaceutically or veterinarily acceptable salt thereof,whereinR1 is Me, Cl, Br or FR2 is F, Cl, Br, C1-C4 haloalkyl or C1-C4 haloalkoxyR3 is F, Cl or BrR4 is H C1-C4 alkyl, C3-C4 alkenyl, C3-C4 alkynyl, C3-C5 cycloalkyl, or C4-C6 cycloalkylalkyl, each optionally substituted with one substituent selected from the group consisting of halogen, CN, SMe, S(O)Me, S(O)2Me, and OMeR5 is H or MeR6 is H, F or Cl andR7 is H, F or Cl.
