Company: VIRBAC

FORMULATION: «oral paste/gel» in pre-charged syringes


  • Oxfendazole: 7 g / syringe of 35 mL, equivalent to 200 mg/mL (=20%);
  • Pyrantel embonate (=pamoate):  9.1 g / syringe of 35 mL, equivalent to 260 mg/mL (= 26%)

CHEMICAL CLASS of the active ingredient(s):



PARASITES CONTROLLED* (spectrum of activity)

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


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

  • 1 mL per 20 kg bodyweight, equivalent to 10 mg oxfendazole/kg bw and 13 mg/kg pyrantel embonate.
  • Each weight marking on the plunger will deliver 5 mL of paste, which is sufficient to treat 100 kg body weight. Each syringe of Strategy-T treats a horse up to 700 kg.


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

Suspected poisoning? Read the articles on oxfendazole safety and/or pyrantel safety in this site.

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

  • MEAT & OFFAL: AUS: Read the product label
  • 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

  • Small strongyles (cyathostomes). Resistance of small strongyles to benzimidazoles is widespread and frequent e.g. in Australia, USA, UK and Europe, Argentina, Chile, Uruguay, etc.  Cases of resistance to pyrantel (cross-resistance with morantel) have been also reported e.g. in Australia, Europe, the USA and Brazil).
  • Parascaris equorum: Cases of resistance to benzimidazoles have been reported (e.g. in Australia and the USA), and of resistance to pyrantel too (e.g. in the EU, USA and Canada)

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:

  • Imidazothiazoles, mainly levamisole. Not approved for use in horses in many countries.These alternative products may not be available in all countries, or may not be available as oral pastes or gels.
  • Macrocyclic lactones: mainly ivermectin, moxidectin. But tolerance or resistance to these compounds have also been reported in Europe (e.g. in the UK, Germany, Italy), the USA, and Brazil.

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: Australia, New Zealand
GENERIC BRANDS available? YES, perhaps not with this particular composition.

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


STRATEGY-T oral paste for horses is a horse wormer from VIRBAC combining oxfendazole with pyrantel.

Oxfendazole is a veteran benzimidazole introduced in the 1960s (by WELLCOME) that is moderately used in livestock and horses, rather scarcely in pets. It is a broad-spectrum anthelmintic effective against roundworms in the gut, but not against those in the skin. It is also ineffective against gastric bots (Gasterophilus spp) or whatever external parasites. It is not used in agriculture.

Pyrantel is a veteran tetrahydropyrimidine introduced in the 1960s (by PFIZER → ZOETIS) that is moderately used in horses, abundantly in pets, but rather scarcely in ruminants. It is a narrow-spectrum anthelmintic effective against roundworms and a few tapeworms (depending on the dose) in the gut, but not against those in other organs (e.g. the lungs, the skin, etc). It is also ineffective against gastric bots (Gasterophilus spp) or whatever external parasites. It is not used in agriculture.

Oxfendazole and pyrantel have no residual effect, i.e. they kill the parasites after administration but do not protect against reinfestation.

The logic oc combining two nematicides (i.e. roundworm killers) such as oxfendazole and pyrantel is related to resistance management. Since both compounds have different mechanisms of action, it is assumed that resistance development will be prevented or at least delayed because the risk of simultaneous development of worm resistance to two different mechanisms of action is much smaller than to only one. However, this is only true if the concerned worms are still susceptible to both compounds. Otherwise, if the worms are already resistant to one of them, only one will work. It will initially do the job, but the risk of development of multiple resistance to both compounds is considerable.

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.