The label says, word for word:
Revolution kills adult fleas and prevents flea eggs from hatching for one month and is indicated for the prevention and control of flea infestations (Ctenocephalides felis), prevention of heartworm disease caused by Dirofilaria immitis, and the treatment and control of ear mite (Otodectes cynotis) infestations.
There are no known contraindications for the use of REVOLUTION PLUS.
Do not use in sick, debilitated or underweight animals.
Prior to administration of Revolution, dogs should be tested for existing heartworm infections.
Sarolaner, one of the ingredients in REVOLUTION PLUS, is a member of the isoxazoline class. This class has been associated with neurologic adverse reactions including tremors, ataxia, and seizures.
Neurologic adverse reactions have been reported in cats receiving isoxazoline class drugs, even in cats without a history of neurologic disorders. Use with caution in cats with a history of neurologic disorders.
Do not come into contact with or allow children to contact the application site until 4 hours post application.
Every approved medicine has a field study behind it, and the label prints what happened:
Following treatment with Revolution, transient localized alopecia with or without inflammation at or near the site of application was observed in approximately 1% of 691 treated cats.
Other signs observed (0.5% or less of 1743 treated cats and dogs) included vomiting, loose stool or diarrhea with or without blood, anorexia, lethargy, salivation, tachypnea, and muscle tremors.
Revolution Plus: In a field safety and effectiveness study, REVOLUTION PLUS was administered to cats with fleas. Reactions reported in the REVOLUTION PLUS group included those presented in the following table.
Revolution: 'Approved by FDA under NADA # 141-152'; the FOI summary for a June 13, 2000 supplement states the original approval was May 26, 1999 (sponsor Pfizer Inc.). Revolution label: 'Revolution is recommended for use in dogs six weeks of age or older and cats eight weeks of age and older for the following parasites and indications.' Dog-only claims: 'Revolution also is indicated for the treatment and control of sarcoptic mange (Sarcoptes scabiei) and for the control of tick infestations due to Dermacentor variabilis.'
The emergency page sorts the signs by how long you have, and the symptom checker asks what you are seeing. Reactions to a medicine can also be reported to the FDA yourself: how to report a problem.
These answers come from the approved label on DailyMed, read on 2 October 2026. Where the label does not say, the answer says so, and the vet or the pharmacist is the one to ask.
The approved use is quoted at the top of this page. The label read for these answers is the one for Revolution, a liquid put on the skin of dogs six weeks of age and older and cats eight weeks of age and older. It kills adult fleas, prevents heartworm disease and treats ear mites in both. In dogs it also treats sarcoptic mange and controls one kind of tick, the American dog tick, and in cats it also treats roundworms and hookworms. Revolution Plus is a different product with a label of its own.
The label says that in controlled laboratory studies more than 98% of fleas were killed within 36 hours, and that in field studies monthly use brought more than 90% control of flea infestations within 30 days of the first dose. It adds that fleas can keep appearing from the surroundings for a short time after treatment starts.
It goes on the skin, and the label says a vet or a vet technician should show you how before the first use. Part the hair at the base of the neck, in front of the shoulder blades, until you can see the skin, put the tip of the tube on the skin and squeeze the tube three or four times to empty all of it in one spot. The label says not to rub it in, not to put it on broken skin or on a wet coat, and to keep it off your fingers. For heartworm prevention it must be given every month. A dog can be bathed two or more hours after treatment without losing the effect against fleas or heartworm; for a cat the label says two hours for fleas and 24 hours for heartworm.
The label says that if a dose is missed and more than a month has gone by, giving Revolution immediately and going back to the monthly schedule keeps the chance of adult heartworms developing as small as possible. It also says that, where heartworm is common, gaps of more than two months during the season when it is passed on raise the risk of the animal getting heartworms.
The studies and the warnings are quoted above. The label has no line telling owners when to call the vet. It does say that stiff or clumped hair, a change in hair color or a slight powdery residue can appear at the spot, and that these are temporary and do not affect the safety of the product or how well it works. If your dog or cat seems unwell after a dose, call the vet. For people, the label says the liquid may irritate skin and eyes, so wash your hands after use and wash any of it off your skin straight away with soap and water.
Store it below 86°F. It is flammable, so the label says to keep it away from heat, sparks, open flames and other sources of ignition. Keep it out of the reach of children.
The label says to discard empty tubes in the ordinary household trash. For tubes that were not used, the FDA says the best way to get rid of most unused or expired medicines is a take-back option: a drug take-back location, which can be at a pharmacy or a police station, or a prepaid mail-back envelope. If you cannot use one and the medicine is not on the FDA's flush list, the FDA says to mix it with something unappealing such as dirt, cat litter or used coffee grounds and to seal the mixture in a plastic bag before throwing it away. Flushing is only for medicines on that list, such as opioids. Do not give leftovers to another pet.
Write the dose, the times and the stop date here, then print this page for the fridge.
Dose and times: _____________________________________________
Stop date: _____________________________________________