Febantel is a broad-spectrum antiparasitic active ingredient used in veterinary medicine in pets and livestock against internal parasites (roundworms, tapeworms). It is not used against agricultural and household pests. It belongs to the chemical class of the pro-benzimidazoles.

Common name:  FEBANTEL

Type: veterinary medecine
Chemical class: pro-benzimidazole


Molecular structure of FEBANTEL 


Type of action: broad-spectrum nematicide and taenicide anthelmintic, endoparasiticide
Main veterinary parasites controlled: gastrointestinal and respiratory roundworms (= nematodes) and tapeworms

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.


Click here to view the article in this site with the most common dosing recommendations for febantel used in domestic animals.


Oral LD50, rat, acute*: 1760 mg/kg
Dermal LD50, rat, acute*: not found
* 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

* Corresponds to fenbendazole sulfoxife and sulfone. This information is an indicator of the acceptance of an active ingredient by the most influential regulatory bodies for use on livestock.

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 febantel safety (poisoning, intoxication, overdose, antidote, symptoms, etc.).

General information on the safety of veterinary 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

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


Decade of introduction: 1970
Introduced by: BAYER
Some original brands: RINTAL, BAYVERM, DRONTAL
Patent: Expired (particular formulations may be still patent-protected)

Use in LIVESTOCK: Yes, scarce
Use in HORSES: Yes, very scarce
Use in DOGS and CATS: Yes, a lot

Main delivery forms

Use in human medicine: No
Use in public/domestic hygiene: No
Use in agriculture: No
Generics available:  Yes, abundant, especially for pets



In livestock & horses: Yes, as all benzimidazoles, very frequent worldwide in gastrointestinal roundworms in sheep, goats and cattle.
In dogs and cats: No

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


Febantel is a veteran anthelmintic (wormer) compound belonging to the chemical class of the benzimidazoles, but is a so-called pro-benzimidazole, i.e. it is transformed into a benzimidazole once it gets into the host's organism. Febantel is transformed into fenbendazole in the stomach and the intestine of the host, shortly after ingestion. Once transformed its behavior is comparable to the one of fenbendazole.

For horses it is mostly available in the form of feed additives in some countries.

For dogs and cats febantel is available mainly in the form of drenches, tablets, pills, etc, all for oral administration.

For livestock it is used mainly in the form of drenches or feed additives, all for oral administration. There are no injectables or pour-ons with febantel.

For pets it is very often used in combinations that broaden the spectrum of activity. Typical mixtures for dogs and cats include another broad-spectrum nematicide (often pyrantel) and/or another taenicide (e.g. praziquantel).

Efficacy of fenbendazole

Febantel itself has no anthelmintic properties. Therefore its efficacy depends on its successful transformation to fenbendazole and to fenbendazole sulfoxide (= oxfendazole).

As fenbendazole it has a broad-spectrum of activity against gastrointestinal roundworms and lungworms of livestock, including adults and L4-larvae of the most important species (e.g. of the genus Bunostomum, Haemonchus, Ostertagia - Teladorsagia, Trichostrongylus, Cooperia, Nematodirus, Chabertia, Oesophagostomum, Trichuris, Dictyocaulus, etc.) as well as arrested larvae of several species. It is also effective against most livestock tapeworms (e.g. Moniezia, Taenia).

In horses it controls the major parasitic roundworms such as Large Strongyles (Cyathostomins), Small Strongyles (Strongylus spp), Parascaris equorum, etc.

It is also effective against the major parasitic roundworms (e.g. Ancylostoma, Toxocara, Trichuris, Uncinaria) and tapeworms (e.g. Echinococcus, Dipylidium, Taenia, etc.) of dogs and cats.

Febantel has only a limited residual effect. This means that a single administration will kill the parasites present in the host at the time of treatment and protect against re-infestations only for a few more days in ruminants, and only for a few hours in non-ruminants.

At the therapeutic dose fenbendazole is not effective against flukes and whatsoever external parasites.

Unfortunately, resistance of several gastrointestinal roundworms to all benzimidazoles, including fenbendazole is already very high and very frequent worldwide in sheep and goats, slightly lower in cattle. For this reason, the risk that benzimidazoles fail to protect ruminants against gastrointestinal roundworms is considerable worldwide. Resistance of worms to benzimidazoles in dogs, cats, pig and poultry are so far not a serious problem.

Pharmacokinetics of febantel

Following oral administration febantel is absorbed into the bloodstream by >40% and very quickly metabolized to fenbendazole and to fenbendazole sulfoxide (= oxfendazole), which both have a high anthelmintic efficacy.

Interestingly, the oxfendazole produced through metabolism is released back to the rumen, where the bacterial flora reduces it back to fenbendazole. This increases the bioavailability of fenbendazole in ruminants.

Excretion occurs mainly through feces. Excretion in goats is about twice as fast as in sheep. Excretion through milk is rather low. All metabolites in the milk fall below the detectable limit 60 hours after administration.

Influence of parasites. In ruminants, heavy infestations with gastrointestinal roundworms increase the pH in the abomasum, which reduces the solubility of febantel, its absorption into blood and its bioavailability. As a consequence, heavy infestations with gastrointestinal roundworms require a higher dose to achieve the same efficacy. 

Mechanism of action of febantel

Febantel acts on the worms only after transformation to fenbendazole. The molecular mode of action of all benzimidazoles, including fenbendazole, consists in binding to tubulin, a structural protein of microtubules. These microtubules are important organelles involved in the motility, the division and the secretion processes of cells in all living organisms. In the worms the blocking of microtubules perturbs the uptake of glucose, which eventually empties the glycogen reserves. This blocks the whole energy management mechanism of the worms that are paralyzed and die or are expelled.

Since cell division is also disturbed, worm egg production and development is also blocked by benzimidazoles, i.e. most of them also have an ovicidal effect.

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