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

Common name: PROPOXUR

Type: pesticide
Chemical class: carbamates


Molecular structure of PROPOXUR






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


Propoxur 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. Propoxur is still used moderately in dogs and cats, mainly in low-cost sprays, shampoos, soaps, etc. or in insecticide-impregnated collars. It is still used in larvicidal dressings for livestock in some countries (mainly Latin America), otherwise usage in livestock or horses is irrelvant.

Most delivery forms of propoxur (sprays, shampoos, soaps, powders, dressings, etc.) do not allow a precise calculation of the dose rate in terms of mg/kg.

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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*:  50 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: No
  • EU: No
  • USA: No
  • AUS: No

* 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 propoxur 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 products for livestock on dogs and cats, unless they are explicitly approved for both livestock and pets. Pets may not tolerate livestock formulations.

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: 1960
Introduced by: BAYER
Some original brands: BOLFO, BAYGON
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: No
Use in
public/domestic hygiene: Yes
Use in
agriculture: Yes
Generics available: 


In pets: Yes, worldwide in dog and cat fleas (Ctenocephalides spp), cross-resistance with other carbamates and organophosphates.

Visit also the section in this site about parasite resistance to antiparasitics and more specifically to organophosphates.


Propoxur is a broad-spectrum carbamate insecticide abundantly used in dogs and cats in the 1970's to 1990's before the introduction of modern highly effective flea and tick spot-ons.

In livestock it is used only in a few dressings against fly maggots and off-animal for premise and environmental treatment on livestock operations.

It is still used a lot in public and domestic hygiene products.

It is quite effective against all kinds of insects. However, resistance of dog and cat fleas (Ctenocephalides spp) and mosquitoes to carbamates is already quite frequent and products with propoxur may not achieve the expected efficacy.

Pharmacokinetics of propoxur

Topically administered propoxur remains mostly on the hair-coat of the treated animals and is very poorly absorbed through the skin. Treated animals can ingest propoxur through licking or grooming. Absorption of ingested propoxur to blood is very fast. It is also quickly excreted through urine. Rats eliminated up to 85% of the administered dose within 16 hours.

Mechanism of action of propoxur

As all carbamate insecticides propoxur 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.