Carbaryl is an antiparasitic active ingredient used in veterinary and human medicine. It is used in dogs and livestock against external parasites (lice, mites, fleas, fliesticks, etc.). It is also used against agricultural and household pests. It belongs to the chemical class of the carbamates.

Common name: CARBARYL

Other names: CARBARIL

Type: pesticide
Chemical class: carbamates


Molecular structure of CARBARYL







Type of action: Broad-spectrum, contact, non-systemic insecticide.
Main veterinary parasites controlled: flies, lice, fleas, mosquitoes, ticks, mites, fly maggots, etc.

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.


Carbaryl is a contact insecticide and acaricide without systemic effect that belongs to the chemical class of the carbamates. It is effective against several external parasites of pets (e.g. fleas, ticks, lice, mites) and livestock. It is not effective against internal parasites.

Carbaryl is still used moderately in dogs and cats, mainly in low-cost sprays, shampoos, soaps, etc. or in insecticide-impregnated collars. It is still moderately used in swine and poultry, often as a powder, and in larvicidal dressings and a few pour-ons for cattle in some countries (mainly Latin America) against horn flies, cattle ticks.

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

Dosing recommendations for CARBARYL
Delivery Parasites Dose (against carbaryl-susceptible parasites)
Topical (bath) Fleas, ticks, lice, mites 400-1000 ppm (=mg/l) in the wash, dep. on indications.
Topical (pour-on) Flies, lice 1-4 mg/kg, dep. on animal's weight
Topical (pour-on) Lice 1-4 mg/kg, dep. on animal's weight
Topical (spray) Lice 2-10 mg/kg, dep. on animal's weight
Topical (pour-on) Flies, lice, mites 1-4 mg/kg, dep. on animal's weight
Topical (spray) Lice, mites 5000-8500 !!! ppm (=mg/L) in the wash

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*: 850 mg/kg
Dermal LD50, rat, acute*: >5000 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.

MRL (maximum residue limit) established for either beef, mutton pork or chicken meat*:

  • CODEX: Yes
  • EU: Yes
  • USA: Yes
  • AUS: Yes

* This information is an indicator of the acceptance of an active ingredient by the most influential regulatory bodies for use on livestock. An MRL for meat may be established also for agricultural pesticides that are not approved for use on animals but are used on commodities fed to animals. It may be also established in the form of an IMPORT TOLERANCE for active ingredients not approved in a particular country but approved for imported animal commodities.

Withholding periods for meat, milk, eggs, etc. depend on delivery form, dose and national regulations. Check the product label in your country.

Learn more about carbaryl safety (poisoning, intoxication, overdose, antidote, symptoms, etc.).

General safety information for antiparasitics is available in specific articles in this site (click to visit):


Never use agricultural or hygiene products with this or any other active ingredient on livestock or pets, even if there are veterinary products with this same active ingredient approved for use on animals. The formulations for agricultural or hygiene use are different and may be toxic for livestock or pets.

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


Decade of introduction: 1950
Introduced by: UNION CARBIDE
Some original brands: SEVIN
Patent: Expired (particular formulations may be still patent-protected)

Use in LIVESTOCK: Yes, very scarce
Use in
DOGS and CATS: Yes, quite frequent

Main delivery forms:

Use in human medicine: Yes, against lice
Use in
public/domestic hygiene: Yes
Use in
agriculture: Yes
Generics available: 
Yes, a lot


In pets: Yes, worldwide in dog and cat fleas (Ctenocephalides spp), cross-resistance with other carbamates and organophosphates,
In livestock: Yes, cross-resistance with other carbamates and organophosphates, worldwide in houseflies (Musca domestica) and poultry mites (Dermanyssus gallinae).

Visit also the section in this site about parasite resistance to antiparasitics and more specifically to organophosphates that show cross-resistance with carbamates.


Carbaryl is a veteran pesticide, one of the first carbamates introduced in the 1950's.

Use of carbaryl in livestock has always been scarce, because organophosphates and synthetic pyrethroids were more effective. Today carbaryl is only used in a few dusts for pig & poultry, some cattle pour-ons against flies, and a few dressing against fly maggots (myiases).

In pets carbaryl was used a lot in the 1970's to 1990's before the introduction of modern highly effective flea and tick spot-ons. Today it is still used in insecticide-impregnated collars, Shampoos, soaps, powders, etc.

In an evaluation from 2009 the US EPA (Environmental Protection Agency) classified carbaryl as a potential carcinogen and prohibited all carbaryl products for pets. 

Efficacy of carbaryl

Carbaryl is quite effective against all kinds of insectsticks and mites. However, resistance of dog and cat fleas (Ctenocephalides spp), mosquitoes and poultry mites (Dermanyssus gallinae) to carbamates is already quite frequent and products with carbaryl may not achieve the expected efficacy.

Pharmacokinetics of carbaryl

Topically administered carbaryl remains mostly on the hair-coat of the treated animals and is very poorly absorbed through the skin. Treated animals can ingest carbaryl through licking or grooming. Absorption of ingested carbaryl to blood is very fast. It is also quickly metabolized to non-toxic metabolites. Up to 85% of the administered dose is excreted through feces and urine within 24 hours after administration.

Mechanism of action of carbaryl

As all carbamate insecticides carbaryl acts on the nervous system of the parasites (but also of mammals, birds, fish and many organisms!) as inhibitor of acetylcholinesterase (also known as AchE), an enzyme that hydrolyzes acetylcholine (Ach). Ach is a molecule involved in the transmission of nervous signals from nerves to muscles (so-called neuromuscular junctions) and between neurons in the brain (so-called cholinergic brain synapses).

AchE's role is to terminate the transmission of nervous signals where Ach is the neurotransmitter (there are several other neurotrasmitters). By inhibiting the activity of AchE, carbamates prevent the termination of those nervous signals, i.e. the neurons remain in constant activity and excitation, massively disturbing the normal movements of the parasites. The bottom line for the parasites is that they are paralyzed and die more or less quickly. Carbamates bind reversibly to AchE, in contrast with organophosphates, another chemical class of parasiticides, which bind irreversibly to AchE.

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