Unique mode of action is what makes PANACUR (fenbendazole) so effective against the most dangerous parasites of the horse.

  • Proven Safe – Safe for foals, pregnant mares and older horses1,6
  • Works on a wide variety of parasites – Labeled for the control of large and small strongyles (including migrating larvae), pinworms and ascarids (roundworms)
  • Effective on encysted small strongyles – A larvicidal dose is the only FDA-approved treatment for all stages of encysted small strongyles1

  • Reliable protection for foals – Widely recognized as the product of choice for treating ascarids in young horses,2,3,4
  • Combat resistance – May be effective even in the face of prior fenbendazole resistance when used as part of a strategically designed anthelmintic program1
  • Unique Mode of Action – The antiparasitic action of PANACUR (fenbendazole) POWERPAC is due to the inhibition of energy metabolism in the parasite5


PANACUR (fenbendazole) Paste 10% is indicated for the control of large strongyles (Strongylus edentatus, S. equinus, S. vulgaris), encysted early third stage (hypobiotic), late third stage and fourth stage cyathostome larvae, small strongyles, pinworms (Oxyuris equi), ascarids (Parascaris equorum) and arteritis caused by hypobiotic larvae of Strongylus vulgaris in horses.


PANACUR (fenbendazole) Paste 10% is administered orally at a rate of 2.3 mg/lb (5 mg/ kg) for the control of large strongyles, small strongyles, and pinworms. One syringe will deworm two 1,250 lb (568 kg) horses at a dose of 5 mg/kg. For foals and weanlings (less than 18 months of age) where ascarids are a common problem, the recommended dose is 4.6 mg/lb (10 mg/kg); one syringe will deworm a 1,250 lb horse.

For control of hypobiotic (encysted early 3rd stage), late 3rd stage, and 4th stage cyathostome larvae, as well as 4th stage Strongylus vulgaris larvae, the recommended dose is 4.6 mg/lb (10 mg/kg) daily for 5 consecutive days; administer one syringe for each 1,250 lb body weight per day.

Do not underdose. Ensure each animal receives a complete dose based on a current body weight. Underdosing may result in ineffective treatment and encourage the development of parasite resistance.

Consult your veterinarian for assistance in the diagnosis, treatment and control of parasitism.

NOT FOR USE IN HUMANS. KEEP OUT OF REACH OF CHILDREN. Do not use in horses intended for human consumption.


Keep your clinic up to date on the Merck Animal Health line of equine products.

1. PANACUR® (fenbendazole) POWERPAC equine dewormer product label. 2. Reinemeyer CR, Prado JC, Vaala WE. Larvicidal efficacy of fenbendazole against a macrocyclic lactone-resistant isolate of Parascaris equorum in foals. Proceedings of the 55th Annual Meeting of the American Association of Veterinary Parasitologists, 2010, Atlanta, GA, p49. 3. AAEP Parasite Control Guidelines. Revised February 2019. 4. Cribb, NC, Cote, NM, Bouré, LP, Peregrine, AS. Acute small intestinal obstruction associated with Parascaris equorum infection in young horses: 25 cases (1985-2004). N Z Vet J. 2006 Dec;54(6):338-43. 5. Lacey E. Mode of Action of Benzimidazoles. Parasitology Today, vol. 6, no. 4, 1990. 6. The recommended dose for control of 4th stage Strongylus vulgaris larvae, 4.6 mg/lb (10 mg/kg) daily for 5 consecutive days, has not been evaluated for safety in stallions or pregnant mares.