Purina Totalcare Heartwormer, Allwormer and Flea Protection offers complete monthly protection for cats against fleas, heartworm, intestinal worms, ear mites, and lice. It's fast acting and kills fleas at all life stages, prevents heartworm disease, and treats common worms. Waterproof within 2 hours and easy to apply! Dosage & Administration:Apply topically to the skin of your cat in front of the shoulder Blades. DO NOT GIVE PRODUCT BY MOUTH.