The present invention relates to a composition for use as an oral anti-parasitic, the composition comprises one or more of an essential oil which contains gamma-terpinene, and/or carvacrol, and/or thymol, and/or terpinenol, and/or eucalyptol and/or eugenol, an essential oil of genus Cinnamomum, Eugenia, Eucalyptus or a source of saponin. It also relates to a method of preventing or treating parasitic infection in an animal, the method comprising orally administering to said animal a composition comprising one or more of an essential oil which contains gamma-terpinene, and/or carvacrol, and/or thymol, and/or terpinenol, and/or eucalyptol and/or eugenol, an essential oil of genus Cinnamomum, Eugenia, Eucalyptus or a source of saponin.
