Do not use Revolt on sick, weak, or underweight animals. Use only on cats 8 weeks and older. Use only on dogs 6 weeks and older. Prior to administration, dogs should be tested for heartworms. In cats, side effects may include digestive upset and temporary hair loss at application site with possible inflammation. In dogs, side effects may include lethargy, digestive upset and temporary hair loss at application site with possible inflammation. In people, Revolt may be irritating to skin and eyes. Wash hands after use. For complete safety information, refer to the package insert.