Company: ZOETIS

FORMULATION: «spot-on» solution for topical administration on the back of the animals (also called pipettes, squeeze-ons, drop-ons, etc.)


CHEMICAL CLASS of the active ingredient(s):


PARASITES CONTROLLED* (spectrum of activity)

* Can be slightly different in some countries: read the product label!


Recommended minimum dose is 6.0 mg/kg selamectin (=2.7 mg/pound) and 1.0 mg/kg sarolaner (= 0.45 mg/pound)

  • Cats, small 2.8 to 5.55 lbs: 1 tube with 0.25 mL (contains 2.5 mg sarolaner and 15 mg selamectin; equivalent >6.0 mg/kg selamectin and >1.0 mg/kg sarolaner)
  • Cats, medium 5.6 to 11 lbs: 1 tube with 0.5 mL (contains 5.0 mg sarolaner and 30 mg selamectin; equivalent 12.0 to 6.0 mg/kg and selamectin and 2.0-1.0 mg/kg sarolaner)
  • Cats, large 11.1 to 22 lbs: 1 tube with 1.0 mL (contains 10.0 mg sarolaner and 60 mg selamectin; equivalent 12.0 to 6.0 mg/kg selamectin and 2.0-1.0 mg/kg sarolaner)

* Can be slightly different in some countries: read the product label!


  • LD50 (acute oral) in rats: >5000 mg/kg (based on sarolaner and selamectin LD50; formulation LD50 n.a.)
  • Estimated Toxicity Class according to the WHO: U, unlikely to present acute hazard (based on the LD50, learn more)

Suspected poisoning? Read the articles on selamectin safety and sarolaner safety in this site.

WARNING !!!: Never use on cats pipettes approved only for dogs. Never use on small dogs pipettes approved for large dogs. Learn more about spot-ons and their safety.

WARNING on macrocyclic lactones. Dogs of some breeds do not tolerate macrocyclic lactones or other medicines (e.g. emodepside) that can cross the blood-brain barrier. They can suffer more or less serious adverse effects if treated at dose rates slightly higher than the recommended ones. Consequently dosing must be as accurate as possible. This is the case for Collies and related breeds, which have a mutation in the MDR-1 gene that affects the blood-brain barrier and makes it more permeable to such compounds than in dogs without this mutation. Besides Collies, other dog breeds have shown similar problems, although the MDR-1 mutation has not been confirmed in all of them. The breeds more affected by this mutation are (% frequency): Collie (70%), Long-haired Whippet (65%), Australian Shepherd (50%, also mini),  McNab (30%), Silken Windhound (30%), English Shepherd (15%), Shetland Sheepdog (15%), English Shepherd (15%), German Shepherd (10%), Herding Breed Cross (10%). Other less affected breeds are: Old English Sheepdog, Border Collie, Berger Blanc Suisse, Bobtail, Wäller. The only way to be sure that a dog is affected or not is to test for it. As more dogs are tested it is likely that the mutation is discovered in other breeds, or that the frequencies change.

WARNING on heartworm prevention. Heartworm preventatives stop development of microfilariae to adult worms but do not cure infections with adult worms. These preventative medicines are different from those curative anthelmintics that kill the adult worms. Preventatives may kill a few adult worms, but won't kill all of them. If this happens, such dead worms may block lung vessels, which can be seriously harmful, even fatal for the pet. Consequently, heartworm preventatives are usually not administered to pets that are already infected with adult worms (hence the periodic diagnostic tests), because the risk of serious complications is real. The infection has first to be treated with adequate curative anthelmintics before preventative products are administered. This is however not trivial, and also risky for the same reason. Ask your veterinary doctor.

Most heartworm preventatives contain macrocyclic lactones at a dose that kills microfilariae and ensures adequate protection for about 1 month, i.e. treatment has to be repeated monthly. In endemic regions with mild to warm climate it is recommended to treat the pets during the whole year, because mosquitoes can be infective the whole year through.

According to FDA's FOI Summary, the following Adverse Drug Reactions were recorded in clinical studies with this product:

  • Lethargy: 4.3% of treated animals
  • Skin Lesions (not associated with application site): 3.5%
  • Anorexia (lack or loss of appetite): 3.2%
  • Pruritus (itching): 2.5%
  • Hair changes at administration site (alopecia): 1.8%
  • Lesions at administration site (scabbing): 0.7%

In September 2018 the FDA of the USA has alerted pet owners and veterinarians about potential neurological adverse events following the use of products containing isoxazolines. Some treated animals have experienced adverse events such as muscle tremors, ataxia (lack of voluntary coordination of muscle movements), and seizures. This regards all products containing isoxazolines. Most treated animals will not show such adverse drug reactions, but some may be affected.

You may be interested in the following articles in this site dealing with the general safety of veterinary products:


Risk of resistance? YES, mainly in:

There are reports of resistance or tolerance of heartworm microfilariae (Dirofilaria spp) to ivermectin and other macrocyclic lactones such as selamectin in the USA (mainly in the South). This has happened after about 20 years of very intensive use of such compounds there. This may happen elsewhere as well. Currently there are no other once-a-month treatments for heartworm prevention other than those containing macrocyclic lactones.

For the time being there are no alternative once-a-month heartworm preventatives available that are suitable for product rotation with selamectin. Macrocyclic lactones are the only compounds that provide monthly prevention and all have the same mode of action.

Fleas (mainly Ctenocephalides felis) have develop resistance to several  insecticides (e.g. carbamates, organophosphates and synthetic pyrethroids) but not yet to macrocyclic lactones or isoxazolines. Since both selamectin and sarolaner are effective againts fleas but have different modes of action, their combination makes also sense in order to prevent or at least delay flea resistance.

Learn more about resistance and how it develops.


Are the active ingredients of this product ORIGINAL* or GENERICS**?

  • Selamectin: GENERIC (introduced in the 1990s)
  • Sarolaner: ORIGINAL (introduced in the 2015)

*Meaning that they are still patent protected and generics are not yet available
**Meaning that they have lost patent protection and may be acquired from manufacturers of generic active ingredients other than the holder of the original patent.

COUNTRIES where this product is marketed (maybe under another TM): USA and other countries. In some countries (e.g. in the EU) it is marketed as STRONGHOLD PLUS.
GENERIC BRANDS available? NO; so far there are no generic brands available with a similar composition and spectrum of activity.

Click here to learn more about GENERIC vs. ORIGINAL drugs.


REVOLUTION PLUS is ZOETIS' (formerly PFIZER Animal Health) original brand for their once-a-month spot-on combining sarolaner and selamectin to provide monthly control and/or prevention of fleas, ticks, mites, heartworms, roundworms and hookworms in cats.

Sarolaner is a broad-spectrum insecticide and acaricide belonging to the isoxazolines introduced in 2015 (by ZOETIS). REVOLUTION PLUS is the second product with sarolaner introduced by ZOETIS, the first one being SIMPARICA, for oral (not topical) administration to dogs. Sarolaner is effective against fleas, ticks and mites. It is ineffective against any worm species. For the time being sarolaner is used excusively in pets, not in livestock or horses. It is not used in agriculture either, nor in vector control or against household pests.

Selamectinn is a macrociclic lactone introduced in the 1990s (by PFIZER → ZOETIS). It is moderately used in pets, but neither in livestock, nor in crop protection or vector control. It is the only macrocyclic lactone that controls fleas. Tick control is usually insufficient because several important species are not controlled (e.g. Amblyomma americanumIxodes spp, Rhipicephalus sanguineus, etc.).

Administered about every 4 weeks, REVOLUTION PLUS controls established flea and tick infestations and prevents flea populations to develop in the pets environment, but only if all the dogs and cats in the same household are treated against fleas. It is also a heartworm preventative and kills some mites and gastrointestinal roundworms.

Both selamectin and sarolaner have a systemic mode of action, i.e. after administration they get into the blood of the host and reach the parasites everywhere in the host's body. For this reason most blood sucking parasites controlled (mainly fleas & ticks) have to bite the treated host to be killed.

REVOLUTION PLUS is not an all-in-one spot-on although it controls many important cat parasites: e.g. mosquitoes, tapeworms and several roundworms are not controlled. In fact, for the time being, there is no such an all-in-one monthly tablet or spot-on available for cats or dogs.

For an overview and a list of the most popular pet antiparasitics for flea & heartworm control click here.


This article IS NOT A PRODUCT LABEL. It offers complementary information that may be useful to veterinary professionals and users that are not familiar with veterinary antiparasitics. 

Information offered in this article has been extracted from publications issued by manufacturers, government agencies (e.g. EMEA, FDA, USDA, etc.) or in the scientific literature. No guarantee is given on its accuracy, integrity, sufficiency, actuality and opportunity, and any liability is denied. Read the site's DISCLAIMER.

In case of doubt contact the manufacturer or a veterinary professional.