Revolution (Selamectin) for Cats: Uses & Coverage

This information is for educational purposes only. Never give your pet any medication without your veterinarian's guidance. Dosing, frequency, and safety depend on your pet's specific health profile.

Revolution is a prescription topical antiparasitic for cats. Its active ingredient is selamectin, a macrocyclic lactone that is applied to the skin, usually at the base of the neck, once every 30 days. In cats, labeled products provide a minimum dose of 6 mg/kg monthly. Your vet chooses the correct tube size based on your cat's body weight and age.

For many pet parents, Revolution is appealing because one monthly medication can cover several common parasites at the same time. It is FDA-labeled for cats and kittens 8 weeks of age and older, and it is used as part of a prevention plan rather than a one-time fix for every situation.

Revolution is not the same product as Revolution Plus. Standard Revolution contains selamectin only. Revolution Plus combines selamectin with sarolaner, which adds tick coverage but also adds isoxazoline-specific neurologic cautions. If your cat's box says only "Revolution," it does not include tick protection.

In cats, Revolution is commonly used for flea control and prevention, heartworm prevention, ear mite treatment and control, and treatment of certain intestinal worms, especially roundworms (Toxocara cati) and hookworms (Ancylostoma tubaeforme). CAPC and Merck list selamectin as a monthly topical option for these labeled parasite targets.

That broad coverage matters because cats often carry more than one parasite at the same time. A cat with fleas may also be at risk for flea allergy dermatitis, tapeworm exposure through fleas, or environmental contamination in the home. A monthly preventive can reduce reinfestation pressure while your vet decides whether your cat also needs ear cleaning, deworming follow-up, or treatment for itchy skin.

Your vet may also use selamectin in some extra-label situations when the evidence and your cat's needs support it. For example, Merck notes selamectin use in some mite-related conditions. Extra-label use should always come from your vet, because the diagnosis, dosing interval, and follow-up plan may differ from the standard monthly label.

Revolution is typically given once every 30 days as a topical liquid placed directly on the skin, not on the hair coat. The labeled feline dose is a minimum of 6 mg/kg monthly, and the correct tube is chosen by weight. Cats should be at least 8 weeks old before starting labeled use. Do not split tubes, guess at the dose, or use a dog product unless your vet specifically instructs you to do so.

Application technique matters. Part the hair at the base of the neck, place the tip on the skin, and empty the tube in one spot where your cat is less likely to lick it. Let it dry fully before close contact with other pets or children. If you miss a dose, give it when you remember and then restart a new monthly schedule from that date, unless your vet advises something different.

Because Revolution helps prevent heartworm disease rather than treating adult heartworms, your vet may recommend heartworm testing before starting or restarting prevention, especially if doses were missed. Monthly consistency is important. Skipping doses can leave gaps in protection even if your cat stays indoors.

Most cats tolerate selamectin well, but side effects can still happen. The most common concerns are mild application-site reactions, such as temporary hair stiffness, clumping, residue, or mild irritation where the medication was placed. Some cats may also show vomiting, diarrhea, decreased appetite, lethargy, itching, sneezing, or conjunctivitis.

If a cat licks the product before it dries, pet parents may notice drooling, foaming, soft stool, or vomiting because the liquid tastes bitter. That can look dramatic, but it is often short-lived. Still, call your vet if signs are intense, persistent, or your cat seems weak, disoriented, or painful.

See your vet immediately if your cat develops facial swelling, hives, trouble breathing, severe skin irritation, collapse, or any other concerning reaction after application. Also contact your vet if your cat is very young, underweight, ill, or has a complicated medical history, because those factors can change how cautiously any parasite preventive should be used.

Published veterinary references report no known major drug interactions for selamectin when used as directed. In FDA-reviewed labeling for selamectin products, the drug has been used safely alongside other commonly used veterinary medications. Even so, that does not mean every combination is automatically right for every cat.

The biggest practical concern is overlap with other parasite preventives or dewormers. Using multiple products with similar goals can increase the chance of duplicate therapy, dosing confusion, or unnecessary side effects. Tell your vet about everything your cat receives, including prescription medications, over-the-counter products, supplements, and any flea treatment bought online or in a store.

If your cat has a history of medication reactions, seizures, chronic illness, or is pregnant or nursing, bring that up before starting any monthly preventive. Your vet can help you compare options and decide whether Revolution, another preventive, or a different parasite plan fits your cat's health profile and household risk.