Times Have Changed. Your Horse’s Parasite Control Program Should Too.

Combat today’s most harmful parasites with the experts’ deworming treatment of choice.

By Kenton Morgan, Senior Veterinarian, Equine Technical Services, Zoetis  

Decades ago, large strongyles (bloodworms) posed the greatest threat to horse health. But thanks to modern dewormers, this parasite can be more easily controlled and should no longer keep you up at night. The greatest parasite concern for adult horses today is the small strongyle1, making it imperative that your horse receives timely treatments each year. Do you know whether your horse has the necessary protection against small strongyles?

Small strongyles, big threat
Small strongyles pose significant risks for adult horses because their larvae (immature parasites) can burrow into your horse’s intestinal lining. This part of their lifecycle is called “encysting.” The emergence of these encysted larvae from the gut wall can be extremely concerning. Experts believe this process can cause harmful inflammation of the gut, which could be associated with a host of serious health problems such as increased risk for colic and weight loss over the course of your horse’s adult life. 

The American Association of Equine Practitioners (AAEP) Parasite Control Guidelines specifically recommend treating the encysted stage of small strongyles at least once per year to protect your horse’s health.

The must-have dewormer active ingredient 
Two deworming active ingredients are currently labeled as effective against the encysted form of small strongyles – moxidectin and fenbendazole. However, due to the evolving issue of parasite resistance, research studies have demonstrated that fenbendazole is no longer effective against small strongyles.1,2 

 In two recent blinded anthelmintic efficacy studies performed in the U.S. with two different equine populations have documented a clear loss of larvicidal efficacy of the five-day double-dose fenbendazole regimen, whereas moxidectin had intact larvicidal efficacy in both studies.2 

Based on AAEP guidelines, moxidectin remains effective against small strongyles, and the deworming option experts recommend. 

Give your horse highly effective parasite control 
Moxidectin, the active ingredient exclusive to QUEST® Gel and QUEST® PLUS Gel in the United States, is the treatment of choice for treating small strongyles. QUEST Gel is the only dewormer approved by the U.S. Food and Drug Administration to control encysted stages of small strongyles, large strongyles, pinworms, bots (and other labeled parasites) in a single dose, making it the optimal treatment option for deworming. It also can suppress small strongyle eggs for 90 days, making it a powerful choice for parasite control.3 

Deworm like the experts
To minimize parasite resistance and maximize results against small strongyles, tapeworms, and other parasites, every adult horse should be dewormed in the spring, at the beginning of grazing season in your region, and in late fall/early winter, toward the end of grazing season in your region. One or both of these treatments should target the encysted form of small strongyles, and the fall treatment should also target tapeworms.  

While this twice-annual deworming is the minimum that parasite experts recommend for all adult horses, it’s important to also have your veterinarian conduct a fecal egg count (FEC) test on each horse in your care at least once per year. This FEC will identify horses in your herd that are “high parasite egg shedders” and may need a third, and possibly fourth, deworming treatment for small strongyles over the course of the year. 

Give your best friend the parasite protection he deserves by using QUEST Gel in the spring and QUEST PLUS Gel in the fall. Both products are the only option that provides moxidectin – the active ingredient that equine parasite experts recommend. This valuable and effective deworming solution, along with these deworming protocols, provides your horses with the protection they need from the most concerning parasites.

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

Do not use QUEST Gel or QUEST PLUS Gel in foals less than 6 months of age or in sick, debilitated and underweight horses. Do not use in other animal species, as severe adverse reactions, including fatalities in dogs, may result.

About Zoetis 
Zoetis is the leading animal health company, dedicated to supporting its customers and their businesses. Building on more than 65 years of experience in animal health, Zoetis discovers, develops, manufactures and commercializes medicines, vaccines and diagnostic products, which are complemented by biodevices, genetic tests and precision livestock farming. Zoetis serves veterinarians, livestock producers and people who raise and care for farm and companion animals with sales of its products in more than 100 countries. In 2019, the company generated annual revenue of $6.3 billion with approximately 10,600 employees. For more information, visit ZoetisUS.com.

For more information, contact: 
Jessica Normand 

1 American Association of Equine Practitioners. Parasite Control Guidelines. https://aaep.org/guidelines/parasite-control-guidelines. Accessed May 20, 2020. 
2 Reinemeyer et al., 2015; Bellaw et al.,2018. Accessed May 20, 2020. 
3 Mason ME, Voris ND, Ortis HA, Geeding AA, Kaplan RM. Comparison of a Single Dose of Moxidectin and a Five-Day Course of Fenbendazole to Reduce and Suppress Cyathostomin Fecal Egg Counts in a Herd of Embryo Transfer-Recipient Mares. J Am Vet Med Assoc. 2014;245(8):944-951.*



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