Horse Deworming

We’ve all heard about the dangers related to gastrointestinal equine parasites along with the many myths associated with horse deworming. Furthermore, deworming can be a little confusing and sometimes overwhelming.  Such as,  completely understand the impact of intestinal worms, the most common of equine diseases.

Horses typically get worms when turned out with previously infected horses or when they are turned out in a contaminated pasture. For example, in both situations, it is highly likely the horse will become infected, as well. Pastures become contaminated with the eggs and larvae of parasitic worms through the manure of an infected horse’s manure which then mixes in the grass of the pasture. Subsequently, As your horse grazes, the eggs and larvae are ingested. A pasture can stay infected for a considerable amount of time so always keep the threat of horse worms in mind.

What parasites can affect a horse?

The four most common types of internal parasites are Strongyles, Ascarids, Tapeworms, and Bots. Each species of parasite affects a horse in its own way.


  • Strongyles (blood or red worms)

Found as three different species – S. vulgaris (up to 25mm), S. edentatus (up to 40mm), and S. equinus (up to 50mm). Strongyle infection occurs by the ingestion of the larvae, which begin their transformation into parasites as they travel down the animal’s intestine. The S. Vulgaris can cause damage in the cranial mesenteric artery, eventually causing colic, gangrenous enteritis, or intestinal stasis and possibly rupture. The other two species are active blood feeders that can lead to anemia, weakness, evacuation, and diarrhea.


  • Ascarids (roundworms)

    The larva of this nasty worm starts its growth in the small intestine and then migrate through the liver, the lungs, and finally, the pharynx or throat where it gets swallowed again. The worm returns to the small intestine to mature and reproduce. Roundworms are an issue with younger horses up to about 15 months of age because of their lack of immunization against the worms. A small infestation will probably have a negligible impact on the horse’s health; however, a heavy infection can trigger weight loss, stunt the young horse’s growth, give a rough hair coat, and/or pot-bellied appearance, and cause lethargy and/or colic.

  • Tapeworms

    Tapeworms take a different approach to infecting your horse. Forage mites in the grass eat tapeworm eggs; the tapeworm larvae then develop within the mites. The horse ingests the forage mites during grazing. Now that the larvae are in the horse’s gut they can develop into maturity. They adhere to the gut wall at the ileocaecal junction, thusly increases the risk of intestinal obstruction or rupture due to inflammation at the attached site.

  • Bots

    Adult flies lay yellow-colored eggs to the horse’s forelegs, chest, and shoulders. As the horse grooms itself, the horse’s saliva releases the egg adhesive and the larvae then enter the mouth. Once ingested, the larvae travel and attach to the lining of the stomach when it causes irritation, digestive issues, and obstruction. After 8-10 months, the larvae are passed in the feces and then burrow into the ground to pupate. They surface from the ground as adult flies and repeat the cycle.

How do I know if a horse has worms?

While a horse may appear to be in good health, it still can be infected with worms. Common signs of parasite infection in both younger and older horses include:

  • Lethargy
  • Loss of weight
  • Loss of condition
  • Diarrhea
  • Colic
  • Lack of appetite
  • Dull coat

For the most part, the best method for confirming whether or not a horse has worms is to have your vet perform a fecal egg count and blood test. Furthermore, these tests confirm the species of parasite; provide an idea of how many adult worms are in the intestine, and give an estimate on how badly your pasture is infested. As a result of the blood test measures chemicals in the blood produced by inflammatory responses to the migration of the larvae.

Which type of wormer removes which parasites?

We at Hillandale Quality Feeds offer a variety of wormers available to treat a number of parasites. Stop by and we can assist you with all of your equine health, nutrition, and worming needs.


Quest Gel        Quest

  • Effective ingredients: The active ingredient moxidectin is shown to be 99.9% effective against small strongyles.
  • Targeted control: Treats and controls small strongyles, bots, and roundworms.
  • Long-lasting parasite suppression: FDA-approved to suppress the production of small strongyle eggs for 90 days.
  • Potent protection: Dewormer can treat horses weighing up to 1500 pounds.
  • Convenient paste: Easy-to-use syringe for fast and accurate application.
  • Active Ingredient: Moxidectin/mL (2.0% w/v)
  • Springtime Wormer


Anthelcide EQ  Anthelcide

  • Effective ingredients: The active ingredient oxibendazole is shown to be effective against benzimidazole-resistant strongyles.
  • Broad-spectrum control: Treats and controls small strongyles, large strongyles, large roundworms, pinworms, and threadworms.
  • Safe formula: This horse product is formulated to offer a wide margin of safety.
  • Potent protection: Dewormer can treat horses weighing up to 1200 pounds.
  • Convenient paste: Easy-to-use, weight-marked syringe for fast and accurate application.
  • Active Ingredient: 22.7% Oxibendazole
  • Summer Wormer

Quest Plus        Quest Plus

  •  Large strongyles, Small strongyles, Encysted gnathostomes, Ascarids, Pinworms, Hairworms, Large-mouth stomach worms, Horse stomach bots, Tapeworms
  • Quest Plus Equine Oral Gel by Zoetis is effective in the treatment and control of parasites.
  • Dose at 0.4mg moxidectin and 2.5mg praziquantel per 2.2 pounds of bodyweight.
  • The syringe can dose a 1,500-pound animal.
  • 2% Moxidectin – an anthelmintic drug that kills parasitic worms and helps prevent and control heartworm and intestinal worms.


  • Not for Human Consumption: This product is intended for horses, and is for animal use only.
  • Effective against: Tapeworms, large and small strongyles, pinworms, ascarids, hairworms, large-mouth stomach worms, bots, lungworms, summer sores caused by habronema and draschia spp. cutaneous third-stage larvae, and dermatitis caused by neck threadworm.
  • Tastes great: Smooth, quick-dissolving apple-flavored paste.
  • Easy dosages: Calibrated, easy-to-use syringe/applicator for more accurate dosing.
  • Potent protection: Full dose contains enough active ingredients to treat horses up to 1320 pounds.
  • Safe for horses of all ages: Only a combination of ivermectin/praziquantel dewormer safe for all horses, including foals as young as four weeks, pregnant/lactating mares, and breeding stallions.


  • Administered as a single oral dose of 3 mL of pyrantel base per pound of body weight.
  • The syringe has four weight mark increments.
  • Each weight mark indicates the recommended dose for 300 pounds of body weight.
  • This wormer is effective in preventing and removing small and large strongyles, pinworms, and roundworms in horses and ponies.
  •  Apple flavored for a more palatable taste!

Zimectrin Gold

  • Effective ingredients: Combination of ivermectin and praziquantel controls parasites and tapewors.zimecterin
  • Powerful protection: Approved to control more species and stages of equine parasites than any other brand.
  • Broad-spectrum control: Treats and controls tapeworms, small strongyles, large strongyles, bots, ascarids, pinworms, summer sores, lungworms, hairworms, large-mouth stomach worms, neck threadworms, and intestinal threadworms.
  • Tapeworm control: First dewormer FDA-approved to effectively control tapeworms with a single dose.
  • Convenient paste: Easy-to-use syringe for fast and accurate application.



  • Works on a wide variety of parasites ‐ Labeled for the control of large and smallsafeguard strongyles (including migrating larvae), pinworms and ascarids (roundworms)
  • High degree of safety ‐ Safe for foals and pregnant mares, older horses, thin and underweight horses, miniature horses, the environment and for use around other farm animals and pets.
  • Easy-to-administer ‐ A unique apple-cinnamon flavor that horses readily accept


We at Hillandale Quality Feeds offer a variety of wormers available to treat a number of parasites. Stop by and we can assist you with all of your equine health, nutrition, and worming needs.

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