This invention relates to methods for controlling parasitic infestations of animals and their environments, and, more particularly, to methods using isoxazolines to control parasites in or on animals or in their environments, as well as treat parasitoses of animals. The isoxazolines include 4-(isoxazolinyl)-benzamides (specifically, substituted 4-(5-(halomethyl)-5-phenyl-isoxazolin-3-yl)-benzamides) and 4-(isoxazolinyl)-benzothioamides (specifically, substituted 4-(5-(halomethyl)-5-phenyl-isoxazolin-3-yl)-benzothioamides). This invention also relates to compositions comprising the isoxazolines for use in such methods, the use of the isoxazolines to make medicaments for use in such methods, and kits comprising the isoxazolines for carrying out such methods. This invention further relates to the use of the isoxazolines as medicaments, particularly medicaments that can be used in the above-referenced method.