Last updated on March 23rd, 2020 at 10:24 am
Are you looking for the best horse wormer and a proper horse deworming schedule?
Picking the best horse wormer is not quite as simple as picking a dewormer for your dog. This is because it is recommended to rotate different dewormers for your horse depending upon the seasons. To find out why a horse wormer rotation is recommended, continue reading below. Of, if you just want our top picks for the best horse dewormers, check out the following chart.
- Best For Spring: Durvet Ivermectin Paste Equine Dewormer
- Best For Summer: Pfizer Strongid Dewormer Paste
- Best For Fall: Merial Zimecterin Gold Dewormer Paste
- Best For Winter: Merck Animal Safe Guard
Best Horse Wormer Comparison Chart
BEST FOR SPRING
BEST FOR SUMMER
No products found.
BEST FOR FALL
No products found.
BEST FOR WINTER
Durvet Ivermectin Paste Equine Dewormer – Best Horse Wormer For Spring
Durvet Ivermectin Paste Equine Dewormer is the best horse wormer for Spring.
There are several reasons why this is the best horse dewormer for Spring. First, it removes bots and worms with just a single dose. Also, it is an easy to administer paste-gel formula, which is apple flavored, so horses love it. Application is a cinch with the easy-to-use syringe.
This equine dewormer for Spring is also safe for all horses, including young foals, breeding stallions, and broodmares. It is effective against Pinworms, Strongyles, Ascarids, Bots, and several other common worms in horses. In fact, this is considered to be the best wormer for pinworms in horses.
Pfizer Strongid Dewormer Paste – Best Horse Wormer For Summer
No products found.
No products found. is our top pick for the best horse wormer for Summer.
Stongid Paste has been proven to safely control and remove various worms and internal parasites in both ponies and horses. These include pinworms, roundworms, small strongyles, and mature infections of large strongyles. That’s why this is the best horse wormer for Summer.
The active ingredient, pyrantel pamoate, is safe for young foals, ponies and horses, including pregnant, breeding, and lactating mares. In fact, some consider this to be the best wormer for pregnant mares. As with any medication, some horses may not like the taste of this Summer horse dewormer.
Merial Zimecterin Gold Dewormer Paste for Horses – Best Horse Wormer For Fall
No products found.
No products found. is our top choice for the best horse wormer for Fall.
Merial Zimecterin Gold Dewormer Paste for Horses was the first horse dewormer licensed in the United States for the control of horse tapeworms. Zimecterin Gold is a combination of ivermectin with praziquantel which offers the broadest spectrum of parasite control that is currently available for equine.
Praziquantel has been proven to be very safe and effective for treating tapeworms in horses. Zimecterin Gold can be given to equine 2 months of age and older. However, be aware that testing has not been done in breeding stallions or breeding mares.
Merck Animal Safe Guard Equine Dewormer – Best Horse Wormer For Winter
Merck Animal Safe Guard Equine Dewormer is our favorite pick as the best horse wormer for Winter.
Merck Safe-Guard horse dewormer is effective on a wide range of parasites, including ascarids, pinworms, and small and large strongyles. Many consider this to be the best wormer for strongyles, but be sure to check with your vet on adequate dosages. It has proven to be safe for pregnant mares and foals, underweight horses, older horses, and miniature horses.
Just like all of our selections above, this one also comes in an easy-to-use application. The apple-cinnamon flavor means that most horses enjoy the taste.
Best Horse Wormer Rotation & Deworming Schedule
For the best horse wormer rotation & deworming schedule, we recommend following the guidelines from The Veterinary Teaching Hospital at Colorado State University, which you can view below or download here.
The reason for rotating horse dewormers is to give your horse a broader spectrum of coverage, since each variation of wormer has efficacy against different worms and parasites and during different stages of the worm’s life cycle. By rotating dewormers, you give your horse better protection from the four main species of internal parasites which infect equine: bots, pinworms, ascarids, and strongyles.
Rotating dewormers also helps to prevent worms from developing resistance to the ingredients used to make deworming products. For a long time, resistance was a constant threat with horse wormers, until the introduction of ivermectin. Ivermectin, which came to market around two or three decades ago, represented a new “class” of wormer for horses, and one of it’s promises was that resistance would not be a problem any longer. Thus far, that has remained true, but many scientists feel that if there is over-use of ivermectin, that sooner or later there will be born some resistant worms. Therefore, it is still recommended to rotate the best dewormers for horses, in order to protect the potency of ivermectin.
How Often Should You Worm A Horse
Typically, most veterinarians will recommend deworming your equine every two months. Most also seem to agree that it is important to avoid repeated use of the same horse wormers. We advise that you consult with your vet prior to starting a horse worming schedule. Below are some of the factors to take into consideration to determine the best horse dewormer to use:
- Age of the horse
- Fecal egg count test performed by your veterinarian
- Use the best dewormer for the given season
- Even stabled horses can get worms
- Use only the drugs which are required to kill the parasites that are detected in the FEC test.
- Follow dosage directions carefully. Under-dosage is a problem if the horse does not consume the full suggested dosage.
Your vet is the best one to contact should you have any questions on designing the best horse worming schedule for your animals.
Best Horse Wormer Buyer’s Guide
There are many dangers associated with gastrointestinal horse parasites as well as many deworming myths as they are one of the most well known equine diseases. Understanding the impact that intestinal worms are having on your horse can be difficult. We frequently get asked questions are “When should I worm my horses?”, “How often should I worm my horse?”, and “what parasites are affected by wormers?” Because of this we have created this guide to help you better understand the best horse wormers, and to plan a better worming schedule.
Horse Worm Symptoms
Even though your equine may appear to be in excellent health, it can still be infected with parasites. Common horse worm symptoms in both older and younger and older equine include:
- Diarrhea or other digestive issues
- Lethargy / lameness
- Dull coat or shedding
- Weight loss
- Lack of appetite
The best way to confirm if your horse has parasites is to visit your veterinarian and have them do a blood test and fecal egg count. These two tests will confirm the type of parasite, give you a rough idea of burden of infestation, and provide an estimate of how much your pasture may be infested.
How Do Equine Get Worms?
A horse can get worms by being exposed to other infected horses or being exposed to a contaminated pasture. In these types of situations it is very likely that your equine will get infected as well. A pasture becomes contaminated when larvae and eggs and of parasitic worms are deposited into the soil and grass by the manure of an infected horse. A horse gets infected by ingesting the contaminated grass, a pasture can remain contaminated for a decent amount of time, so be sure to keep horse worms in mind.
Controlling Worms In Horses
There are basically three pivotal steps for controlling parasites effectively. We recommend that you consult with your vet for the most effective protocol for your particular equine.
Step 1: Managing the pastures – Try to keep the level of eggs and larvae to a minimum in the pasture.
- Frequently remove and properly dispose of feces. Doing so twice per week will have a significant positive effect to keep egg and larvae populations low. Mowing and harrowing your pasture will also expose the parasites to the elements and predators, thus helping to decrease the population.
- Pasture rotation – Allow horses to roam different pastures throughout the year. If possible, try to let each pasture rest for around six months.
- Rather than ground feeding, feed grain and/or hay in a rack.
Step 2: Monitoring parasite fecal egg counts – Keep a close eye on FEC’s in order to diagnose parasites stick to an effective horse deworming schedule.
Step 3: Worm your equine – Giving your horse the best horse wormer helps to ensure that adult worms are removed from the intestine and greatly reduces the chance of parasite re-infection by drastically lowering the number of ineffective worm larvae in the feces.
Which Parasites Affect Horses?
There are four well known types of internal parasites, Ascarids, Strongyles, Bots and Tapeworms. Each parasite can affect a horse in different ways.
Larva start in the small intestine where it grows and then travels through the lungs, liver, and eventually, to the throat where the horse will swallow it again. The worm will find it’s way back to the horse’s small intestine where it will grow and reproduce. Younger horses under 15 months old are more prone to roundworms because they lack any sort of immunization against them. A small infestation of the worms will not pose a large threat to your horse’s health. On the other hand, a large roundworm infection can cause weight loss, lethargy, stunted growth, rough coat, and pot bellied appearance.
Mature flies lay their yellow-colored eggs on a horse’s shoulders, chest, and legs. When the horse licks and grooms itself, the eggs are detached and then ingested. The fly larvae travel down the throat and attach themselves to the inside of the stomach where they it cause digestive issues and irritation. In about 8-10 months, the fly larvae are expelled from the horse in the feces. Next, the larvae burrow into the ground in order to pupate. The adult flies soon surface and the cycle is repeated.
Strongyles (red or blood)
There are three different species of Strongyles. Your horse gets infected by ingesting the larvae, when then travel down the intestine of the horse where they become parasites. The S. vulgaris is a nasty parasite which can damage the cranial mesenteric artery and lead to gangrenous enteritis, colic, or intestinal stasis. The other two species of worms feed on blood and can lead to lethargy, diarrhea, anemia, and emaciation.
Tapeworms have a more unique way of infecting your equine. First, forage mites eat the worms eggs, then the eggs develop into larvae inside the mites. After the horse grazes on the infected mites, they reach the intestines of the animal where they mature. There, they attach themselves to the internal gut wall, causing inflammation. This then increases the horse’s risk of intestinal obstruction or rupture.
Treating your horse with the best horse wormer on a proper horse deworming schedule can effectively manage and rid your horse of parasites. It is important to use the correct medicine to treat the worms that your horse has. Rotating horse wormers is recommended, to help reduce the chance of parasites building resistance to the drugs. Always speak with your vet prior to starting a worming program.
Last update on 2020-04-07 / Affiliate links / Images from Amazon Product Advertising API