XENO 450 is designed as a topical spot on for use on rabbits, guinea pigs and ferrets. The active ingredient Ivermectin is a substance known as an endectocide because it kills parasites that cause infestation inside the body (endoparasites) as well as those living outside the body, on the skin (ectoparasites). Ivermectin is used in many species for the control of mites, roundworms and lice.