Sarolaner is a broad-spectrum antiparasitic active ingredient used in veterinary medicine in pets against external parasites (fleas, ticks, lice, mites, etc.). It is not used against agricultural and household pests. It belongs to the chemical class of the isoxazolines.

Common name: SAROLANER

Type: veterinary medicine
Chemical class: ISOXAZOLINES


 Chemical structure of SAROLANER. Picture taken from


Type of action: Broad-spectrum, systemic ectoparasiticide: insecticide, tickicide, acaricide.
Main veterinary parasites controlled: fleas, (Ctenocephalides felis, Ctenocephalides canis), ticks (EU: Dermacentor reticulatus, Ixodes ricinus, Ixodes hexagonus, Rhipicephalus sanguineus) and mites (Sarcoptes scabiei), screwworms (Cochliomyia hominivorax).

Efficacy against a specific parasite depends on the delivery form and on the dose administered.

Click here for general information on features and characteristics of PARASITICIDES.


Sarolaner is an insecticide and acaricide with systemic mode of action that belongs to the chemical class of the isoxazolines, a pesticide class introduced in 2013. It is available for oral administration (chewable tablets) to dogs for the control of fleas, ticks and a few other external parasites. It is ineffective against any kind of parasitic worms.

The table below indicates some usual dosing recommendations for sarolaner issued by manufacturers or documented in the scientific literature. They may not be approved in some countries.

Dosing recommendations for SAROLANER
Delivery Parasites Dose (against sarolaner-susceptible parasites)
Oral Fleas 2-4 mg/kg; 4-5 weeks protection
Oral Ticks 2-4 mg/kg; 4-5 weeks protection
Oral Generalized demodicosis 2-4 mg/kg
Oral Otodectes cynotis (ear mites) 25-56 mg/kg; up to 3 months protection
Oral Sarcoptes scabiei (canine scabies) 2-4 mg/kg
Delivery Parasites Dose (against sarolaner-susceptible parasites)
Spot-on Fleas 1-2 mg/kg; 4-5 weeks protection
Spot-on Ticks 1-2 mg/kg; 4-5 weeks protection

DISCLAIMER: Liability is denied for any possible damage or harm to persons, animals or any other goods that could follow the transmission or use of the information, data or recommendations in this site by any site visitor or third parties.

Dosing recommendations for antiparasitics depend on national regulations. National regulatory authorities determine whether a product is approved for a given indication, i.e. use on a particular host at a specific dose and against a specific parasiteCheck the labels of the products available in your country for specific information on approved indications.


Oral LD50, rat, acute*: 783 mg/kg
Dermal LD50, rat, acute*: >2020 mg/kg.
* These values refer to the active ingredient. Toxicity has to be determined for each formulation as well. Formulations are usually significantly less toxic than the active ingredients.

Sarolaner is safe for use in dogs, including avermectin-sensitive breeds (e.g. collies), even when used at doses greather than those required for monthly protection against ticks and fleas.

MRL (maximum residue limit) set for animal tissues (e.g. beef, mutton pork or chicken)*: NOT APPLICABLE. Approved only for dogs.
Withholding periods: NOT APPLICABLE. Approved only for dogs.

There is very little knowledge on tolerance in different dog breeds or in young, old or otherwise weak animals.

Since all approved products are for oral administration, no chemical residues are expected to contaminate the hair-coat of dogs after treatment. Therefore, in contrast with products for external use (e.g. spot-ons) there is no risk of contamination of humans (particularly children) getting in close contact with treated animals.

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 in dogs. In August 2021 The FDA has extended this alert to cats. 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.

For additional safety information read the article on sarolaner safety in this site.

General information on the safety of veterinary antiparasitics is available in specific articles in this site (click to visit):


It is obvious that veterinary products are not intended for and should never be used on humans!!!


Year of introduction: 2016
Introduced by: ZOETIS
Some original brands: SIMPARICA
Patent: VALID

Use in

Main delivery forms: 

Use in human medicine: No
Use in
public/domestic hygiene: No
Use in
agriculture: Not
Generics available: 


In pets: No

Learn more about parasite resistance and how it develops.


After afoxolaner and fluralaner, sarolaner was the third active ingredient belonging to the isoxazolines introduced as a veterinary antiparasitic. Isoxazolines are a new class of insecticides discovered in the 2000s. Whereas afoxolaner and fluralaner were licensed from other companies by MERIAL and MERCK AH, respectively, sarolaner was an own discovery and development of ZOETIS, the patent holder, and was selected as the best candidate among several thousand analogues.

Sarolaner is available in the form of chewable tablets for oral administration to dogs (SIMPARICA), i.e. it has a systemic mode of action. Ingested sarolaner is rapidly absorbed into blood and distributed throughout the whole body of the treated dog. Blood-sucking parasites (mainly fleas and ticks) are killed during their blood meal.

But the systemic mode of action means also that for fleas and/or ticks to be killed, they have to bite the dog first and suck enough blood before the ingested active ingredient kills them.

As other isoxazolines with insecticidal and tickicidal efficacy, afoxolaner is a non-competitive GABA (gamma-aminobutyric acid) receptor antagonist, much more selective for GABA receptors in insects or ticks, than for those in mammals, including humans. It binds to chloride channels in nerve and muscle cells, which blocks the transmission of neuronal signals. Affected parasites are paralyzed and die.

Efficacy of afoxolaner

Sarolaner is highly effective against several flea and tick species at very low doses. In studies in vitro it showed to be about 10x more potent than other isoxazolines, with an LD80 of 0.3 mcg/ml =0.3 ppm) against fleas. In the EU, indications for the chewable tablets include control and prevention of fleas, (Ctenocephalides felis, Ctenocephalides canis), ticks (Dermacentor reticulatus, Ixodes ricinus, Ixodes hexagonus, Rhipicephalus sanguineus) and mites (Sarcoptes scabiei) after monthly administration. Contol od Sarcoptes scabiei is quite unique for sarolaner: other isoxazolines do not include this indication. Administered orally to dogs at a dose of 5 mg/kg it provides 5 to 4 weeks days efficacy against fleas and ticks, respectively.

Pharmacokinetics of sarolaner

In pharmacokinetic studies, the highest dose in blood following oral ingestion was reached 3 hours after administration, which ensures a quick onset of efficacy against blood-sucking parasites. Once in the blood, sarolaner binds to plasma proteins to >99.9%. The half-life in blood after oral administration was 12 days and the bioavailability reached <85%. Main elimination was in the form of the parent molecule excreted through the bile and the feces.

Click here to view the list of all technical summaries of antiparasitic active ingredients in this site.