The present invention provides an animal ectoparasite controlling agent and a method for preventing or treating infection in animals caused by parasites by using the controlling agent. An animal ectoparasite controlling agent exhibiting excellent insecticidal activity and a method for preventing or treating infection in animals caused by parasites by using the controlling agent are obtained by using a compound having a pyrazole ring at the 4 position of the piperidine ring as an active ingredient.