Company: ZOETIS

FORMULATION: «oral gel» in pre-charged syringes


CHEMICAL CLASS of the active ingredient(s):



PARASITES CONTROLLED* (spectrum of activity)

* Country-specific differences may apply: read the product label.

  • Large strongyles: Strongylus vulgaris (adults and arterial stages); Strongylus edentatus (adults and visceral stages); Triodontophorus brevicauda (adults), Triodontophorus serratus (adults), Triodontophorus tenuicollis (adults).
  • Small strongyles: Adult and immature (fourth stage larvae) small strongyles or cyathostomes: Cyathostomum spp, Cylicocyclus spp, Cylicostephanus spp,
    Cylicodontophorus spp, Gyalocephalus spp. EQUEST Oral Gel is effective against (developing) intramucosal L4 stages of small strongyles. At eight weeks after treatment early (hypobiotic) EL3 stages of small strongyles are eliminated.
  • Pinworms (adults and larval stages): Oxyuris equi
  • Ascarids (adults and larval stages): Parascaris equorum
  • Hairworms (adults):Trichostrongylus axei
  • Large-mouth stomach worms (adults): Habronema muscae
  • Intestinal threadworms (adults): Strongyloides westeri
  • Stomach bots: Oral and gastric stages of Gasterophilus spp, horse bot flies
  • Adult Tapeworms: Anoplocephala perfoliataAnoplocephala magna, Anoplocephaloides mamillana


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

  • 0.4 mg moxidectin per kg bodyweight (= 400 mcg/kg) and 2.5 mg praziquantel per kg bodyweight.
  • One 14.4 g syringe contains sufficient gel to treat a 700 kg horse at the recommended dose rate
  • Each graduation on the calibrated syringe delivers sufficient gel to treat 25 kg bodyweight.


  • LD50 (acute oral) in rats: >5000 mg/kg (estimate calculated according to the WHO based on the moxidectin LD50)
  • Estimated hazard class according to the WHO: not applicable for veterinary medicines

Suspected poisoning? Read the articles on moxidectin safety and/or praziquantel safety in this site.

Withholding periods (=withdrawal times) for meat & milk (country-specific differences may apply: read the product label)

  • MEAT & OFFAL: Horses: UK: 64 days
  • MILK: Do not use in animals producing milk for human consumption

WARNING !!!: Never use on humans, dogs or cats

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


Risk of resistance? YES

This means that if this product does not achieve the expected efficacy against the mentioned parasites, it may be due to resistance and not to incorrect use, which is usually the most frequent cause of product failure.

Alternative chemical classes/active ingredients to prevent resistance of gastrointestinal roundworms through product rotation:

These alternative products may not be available in all countries, or may not be available as oral pastes or gels.

Learn more about resistance and how it develops.


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


*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): UK, Ireland and other EU countries. In the US marketed as QUEST PLUS. In Australia and New Zealand as EQUEST PLUS TAPE
GENERIC BRANDS available? YES, but not too many.

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


EQUEST PRAMOX oral gel for horses is a horse wormer with moxidectin and praziquantel from ZOETIS. Moxidectin is effective against roundworms and bots, praziquantel against tapeworms.

Moxidectin is a macrocyclic lactone introduced in the market in the early 1990s (by AMERICAN CYANAMID → PFIZER → ZOETIS). It is moderately used in livestock and pets. It is effective against most species of roundworms that affect horses and against bots (Gasterophilus spp), but not against tapeworms.

Moxidectin and other macrocyclic lactones have about two weeks residual effect on horses because they are stored in body fat and progressively released. This, together with the time that worms need to develop inside the horse after infection (pre-patent period) allows to space the treatment intervals to 10 to 12 weeks in year-round control programs in many regions. For other active ingredients that have no residual effect such as fenbendazolemebendazole, or pyrantel the treatment interval is usually 4 to 6 weeks.

Whereas in ruminants moxidectin administered at 400 mcg/kg controls a series of external parasites as well (mites, lice, etc.), such an indication is not approved in most countries in horses: external parasites have to be controlled with ectoparasiticides (e.g. pour-ons, sprays, etc.).

Praziquantel is a veteran anthelmintic introduced in the 1970s (by BAYER). It is highly effective against tapeworms (in horses mainly Anoplocephala spp) but has no efficacy whatsoever against roundworms. It is the anthelmintic most vastly used against tapeworms in horses and pets, used in hundreds of brands. It is hardly used in livestock. Praziquantel has no residual effect, i.e. it kills the parasites after administration but does not protect against reinfestation.

Many horse owners complain about the price of the oral pastes & gels for horses (with ivermectin or other macrocyclic lactones), compared with the much cheaper injectables for livestock with the same active ingredients, used at the same dose (200 mcg/kg). This is why off-label use of livestock ivermectin injectables in horses is very common worldwide, particularly in working horses of cattle and sheep ranches. The reason why injectables are mostly not approved for use on horses is apparently that, shortly after introduction, it was noticed that horses were more prone to develop severe clostridial infections at the injection site (due to contamination of the needles) and other undesired side effects than cattle or sheep. In addition, the pharmacokinetic behavior of ivermectin on horses is different than in ruminants. For these reasons oral pastes were developed for horses that do not show such side effects. However, in numerous countries (e.g. in Latin America) some ivermectin injectables for livestock are also approved for use on horses.

For an overview and a list of the most used oral paste & gel brands 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.