How to deworm a horse

Deworming should be a worry-free, routine practice that takes place several times a year. Is your horse difficult to deworm? If so, he may have had a bad deworming experience. Or doesn’t like the taste of the dewormer. You can train your horse to accept deworming calmly using Clinton Anderson’s step-by-step technique.

How to deworm a horse

Clinton Anderson offers tips to train your horse to accept deworming calmly.

Top trainer/clinician Clinton Anderson explains that most deworming issues aren’t the horse’s fault, it’s the owners’ approach to the process. “Avoid sneaking up to your horse and jamming the dewormer in his mouth,” he says. “Also, don’t walk straight up to your horse, hang on to the halter really tight, then jam the syringe in his mouth. You’ll make him defensive.

“Keep in mind that horses are prey animals,” Clinton Anderson explains. “If you approach him and stick the dewormer in his face, like a predator, then he’s going to stick it back in your face and say, Get lost!’
“On the other hand, if you walk up to your horse and kind of act casual about it, pretty soon, you’ll notice that a lot of his defensiveness will go away and he won’t be worried about getting dewormed.”

A horse that’s good for deworming will stand still with his head down, body relaxed, and readily accept a dewormer, because he realizes that you are not trying to hurt him. It is possible to train your horse to feel comfortable with deworming. Here’s Clinton Anderson’s step-by-step technique to train your horse to accept deworming.

Step 1: Desensitize the Air Space
Use the dewormer to desensitize the air space around your horse’s head. If he won’t accept the dewormer in the airspace around him, then he won’t accept the dewormer in his mouth. Desensitizing works, because you’re doing the opposite of what he expects you to do that is, he expects you to deworm him, but you won’t in this step.

Stand on your horse’s left side, so you’re out of his way if he tosses his head or strikes at you. Wave an empty deworming syringe back and forth around his entire head and muzzle, keeping it eight inches away from his muzzle.

When your horse keeps his head still, immediately stop waving, retreat, and rub his head with your other hand. Repeat this step until he keeps his head still for the entire time that you’re moving the dewormer.

“If he isn’t relaxed at this point, don’t go to the next step.” says Anderson. “Your horse must be relaxed for this to work.”

Step 2: Desensitize to the Syringe
Desensitize your horse to the touch of the deworming syringe. You want him to understand that he can be touched by the dewormer without actually getting dewormed.

Starting at your horse’s withers, rub an empty deworming syringe all over his body. Work back toward his withers, and onto his neck and jaw. If he throws his head or moves away from you, continue rubbing until he stands still and relaxes, then retreat.

Rub the deworming syringe all over your horse’s face, continuing to use the approach-and-retreat method. As he becomes desensitized, gradually rub the dewormer down and around his muzzle.

“When you rub the dewormer around your horse’s nose and face, don’t rub it real slow like you’re sneaking around him hoping that he’ll stand still,” says Anderson. Instead, rub vigorously. He’ll think, Man, you’re an idiot, you don’t even know where my mouth is.

When your horse relaxes, and keeps his head and feet still, retreat the dewormer, and rub his head with your other hand.

“You’re trying to establish a starting point,” says Anderson. “You want him to realize that the quickest way to get rid of the dewormer is for him to stop moving his feet, and to relax his head and neck.

“When he does so, take the dewormer away from him, and rub his face with your other hand. Keep doing this until you can rub the dewormer all over him, and he doesn’t move.”

Step 3: Coat the Syringe
Repeat Step 2, then coat an empty deworming syringe with something sweet, such as honey, molasses, or sugar. This sweet coating will help teach your horse to accept the deworming syringe in his mouth it’ll help him disassociate the bad taste of dewormer with the deworming process. (Give your horse a taste for the sweet coating by putting a little of it on his feed every night.)

Stand on your horse’s left side, and ease the dewormer into the corner of his mouth. Keep the dewormer in his mouth; if he throws his head, raise your arms. If he steps backward, move back with him.

As soon as your horse stands still, lowers his head, and relaxes, remove the syringe and rub his face with your other hand.

Patiently repeat this step until your horse stands still.

Step 4: ‘Deworm with Honey’

Deworming your horse with honey makes him think that whatever is in a deworming syringe tastes good.

Fill the empty dewormer with honey, then wave and rub the syringe around his nose to ensure that he’s desensitized to it. Then place the honey ‘dewormer’ in the corner of his mouth, and slowly ‘deworm’ him by letting him lick the honey off the syringe.

Repeat this step over the course of several days.

Step 5: Deworm Your Horse
When your horse accepts the deworming syringe in his mouth, you can actually deworm him. Repeat Steps 1 through 4 until he shows no defensiveness towards the dewormer. Then get a real dewormer, and put a sweet coating on the outside of the syringe. Put the dewormer in the corner of his mouth, and empty the syringe. Wait for him to digest the dewormer, and immediately follow up with a honey dewormer.

“Always leave your horse with a positive taste in his mouth,” says Anderson. “If you just give the bad-tasting dewormer and walk away, the last thing he remembers is a foul taste.”

Step 6: Follow Up

Over the next three or four days, ‘deworm’ your horse with honey to remind him that deworming doesn’t have to be a horrible experience. Be sure to desensitize him by waving and rubbing the syringe around his nose before putting the honey dewormer in his mouth.

Step 7: Repeat the Process

Deworm your horse with honey once a day for four days before the next scheduled deworming. Follow up by ‘deworming’ him with honey once a day for four days after the deworming. You’ll then leave him with a positive deworming experience. In time, you should be able to just walk up, deworm your horse, and walk away.

Parasites do not want to kill your horse; your horse is the dinner plate. Parasites do not mind robbing the best nutrition from your horse. Deworming a horse is good preventative medicine! With all the options available, you need to determine which dewormers and schedule are best for your horse.

Your horse’s job and living conditions will dictate the number of times you need to deworm. If your horse is what you call a “backyard horse,” then a minimal amount of deworming is needed, as long as you rotate with different types of dewormers. For the horse that stays home, you will probably only need to deworm in the spring, summer, and fall. This will be sufficient enough to prevent from feeding parasites and prevent colic, both good reasons to deworm. Show horses that travel and stabled horses may need dewormer every other month to prevent parasite issues.

If you are behind in deworming, start deworming twice with two different dewormers one week apart and that will catch you up. Follow as needed with rotational deworming.

Why Rotate?

Recommended Deworming Rotation Schedule

Manure Management

In addition, manure management will also help keep the parasite numbers low on your pasture. Parasite eggs are passed in the stool and mature in our pastures. The larvae get into dew droplets on the grass and are grazed down by your horse. Rotate horses between pastures and drag pastures to break up manure, exposing parasites to the sun so they die. Compost all manure before spreading on pastures. Composting will kill the parasite eggs before they are spread on the soil to be picked up again by your horse. Never spread raw manure on pastures. The goal is to decrease the larva load on the pasture your horse grazes!

Rotating dewormers at the correct time and pasture management will prevent parasites from being an issue for your horse.

If you need help, call us at 800.786.4751.

-Dr. B
Don Bramlage, DVM, Former Director of Veterinary Services at Revival Animal Health

How to deworm a horse

Deworming horses can be done in two ways. You can use paste horse dewormers or a feed through horse wormer.

Pelleted type feed-through wormers are a daily additive that you give with your horse’s grain ration. If you use this method, simply follow the instructions on the label.

Paste wormers come in a plastic syringe. The plunger on the syringe is marked off in increments of 250-300 lbs. The plunger also has a little plastic ring on it. This ring is used to set the proper worming dose that you will be giving your horse.

Before you can start deworming horses you have to know how much they weigh. Unless you have access to a giant scale, use an ‘equine height and weight measure tape’. These are very inexpensive horse measuring tapes that can be found at your local feed stores and tack shops.

How to Measure Your Horse’s Weight

With your horse standing on a fairly level surface, take the tape measure and wrap it around your horse’s girth area just behind the withers. Pull the tape snug but not tight and read the measurement. You may try this 2 or 3 times and take the average.

Once you know how much your horse weighs, you are ready to set the dial on your paste wormer to the correct dosage. Twist the plastic ring on the plunger to unlock it. Slide it over to the appropriate weight marked on the plunger and then twist it back down to lock it in place. Remove the small plastic cap on the tip of the syringe.

Giving the Paste Wormer

For the most part deworming horses is easy, but if your horse is not cooperative, it can be challenging. Some people prefer to have their horse tied and some prefer to have their horse free standing. That’s up to you. At minimum you’ll want to halter your horse. I like to tie mine.

The objective is to get your horse to swallow the set dose of paste without spitting any out. If you’re like me and you like to give your horse treats, don’t give them a goody until after they have swallowed the paste. If your horse has a wad of grass in her mouth, she’ll spit the paste and the grass out together in one gooey mess.

When deworming horses, you’ll want to stand to one side of your horse’s head. Place the syringe in the side of your horses mouth, starting at the corner of his lip and sliding it over the gums. Aim the tip of the syringe to the back of the tongue as far back into the horses mouth as you can reach without getting bit. Then quickly push the plunger in to dispense the paste. Try to do this in one swift movement.

Most horses will try and push the syringe out with their very strong tongues. If you can place the body of the syringe between the teeth and the tongue while the tip is aimed to the middle of the tongue, they have a harder time pushing it out.

It has been my experience that the faster you get the syringe in and out of your horses mouth, the more tolerant they are about it. It’s quite common to get the bulk of the paste down and have the horse spit some portion of it out. If this happens, and you have some paste left over in the syringe, you can use it to replace the rejected portion. You’ll have to use your best judgment as to how much was lost and how much you need to give again.

A Great Video on Worming the Hard-to-Worm Horse

If you have a horse that is very uncooperative, and you just can’t get that syringe in their mouth don’t panic. You can often get the paste down your horse by mixing it into a treat. The trick is in cleverly hiding the taste and seeing that they eat their full dose.

I have done this successfully with a mix of cubed apples, diced carrots and a bit of sweet grain with molasses. Stir the dose of worming paste in well. Most horse worming pastes have an artificial apple flavor to help disguise the taste, so it will fit in nicely with your apple/carrot/grain concoction. Just mix enough of this that you know your horse will eat the whole thing.

Worst case scenario, if you absolutely can not get the paste down your horse, you can always use a pelleted feed through horse wormer. Deworming horses is more important that what method you choose to do it with.

FREE Printable Deworming Chart!

Get your own handy deworming chart to keep track of your wormer rotation schedule by clicking here.

by Firn Hyde | Dec 5, 2018

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Why Are Worms Bad for Horses?

The equine digestive system is as delicate as it is essential for your horse’s health and well-being. Worms can cause many different problems. Firstly, these worms obviously have to live on something, and that generally turns out to be one of two things: either your horse’s blood or his partially digested food. Neither is good for your horse’s overall health, and he will lose weight and struggle to perform. With a large enough worm burden, your horse could even become anemic or suffer from malnutrition despite being fed correctly.

Worms are also a major cause of colic. Not only can they cause intestinal pain by biting into the horse’s intestinal walls, but if present in large enough numbers, they can cause a physical blockage somewhere in your horse’s intestine. This is a form of impaction colic that can be deadly if it develops into a perforation or a torsion.

So, it’s essential to make sure your horse’s belly is worm-free. But how do you know if he has worms or not?

Signs of a Worm Burden

Visible signs of a heavy worm burden include:

• Dull coat with long hair

• Pale mucus membranes (anemia)

• A large, low-slung belly, known as a “worm belly”. (This can be confused with a pregnant belly or with a “hay belly” in non-working horses who consume large amounts of roughage, and is not always an indication of a worm burden).

Most horses with significant worm burdens, however, are asymptomatic – you won’t see any of these clinical signs. By the time the horse is visibly “wormy”, his worm burden is astronomical. Your horse could be crawling with worms and you wouldn’t be able to see a thing. The idea is to prevent him from ever having the symptoms of a worm burden, and this is best done using fecal egg counts.

Fecal egg counts are effectively worm tests. These are done on small samples of fresh manure. Your vet or even animal medication company will inspect the manure under a microscope and count the number of worm eggs present per gram (EPG). As a general rule of thumb, horses with an egg count of more than 400 EPG should be dewormed and then have another egg count done to ensure that the anthelmintic (dewormer) worked.

As a general rule, fecal egg counts should be done at least four times a year, depending on your worm burden and management system. Horses on pastures or in group paddocks are at far greater risk of ingesting worms than horses who are stabled and live in individual paddocks. Grazing horses are at the highest risk of worms, especially young horses, as they have no immunity against the worms yet.

Choosing the Right Dewormer

For this reason, the anthelmintic you choose has to be specifically targeted for the type of worms that you have. Your vet will be able to tell you exactly what type of worms your horse has based on his fecal egg count.

When buying an anthelmintic, it’s important to check its active ingredient. Here’s a list of some popular active ingredients, their commercial forms, and the worms they’re effective against.

• Ivermectin: Effective against redworms, roundworms, pinworms, threadworms, and bots. A popular and extremely safe dewormer. Contained in: Duramectin , Zimecterin , Bimectin

• Pyrantel Pamoate: Effective against redworms, roundworms, pinworms, threadworms, and tapeworms; a good option if there is resistance to ivermectin. Contained in: Exodus , Pyrantel Paste

• Oxibendazole: Effective against redworms, roundworms, pinworms, stomach hairworms and large-mouthed stomach worms. Can be used multiple times per day for very heavy worm burdens. Contained in: Anthelcide EQ

• Moxidectin: One of the few ingredients effective against encysted small strongyles. Easy to overdose and must be used with care. Contained in: Quest

How to deworm a horse

The best way to deworm your horse!

  • This used to be as simple as giving a different product every couple of months, willy – nilly, known at rotational deworming.
  • Now, we have learned that many horse parasites are actually resistant to the only dewormers that are available. This is bad. One more piece of bad news – there are no new dewormers currently being created, so what we have is what we have.
  • The American Association of Equine Practitioners (AAEP) has up-to-date guidelines for deworming protocols. These guidelines are long and involved, but give great detail in case you are into that sort of thing.

Why fecal egg counts and targeted deworming are best instead of rotational deworming.

  • It starts with drug resistance. In this case, resistance to anthelmintics which kill worms. Worms and parasites that are unaffected, and therefore are not killed, by these drugs are called resistant. In the case of horse parasites, anthelmintic resistance is a growing concern.

How to deworm a horse

A fecal egg count test is easy! A sample of your horse’s manure is collected and send via mail for testing. The lab does the rest! Always work with your veterinarian when creating a fecal testing and deworming program for your horse, it’s typically in the spring and the fall.

  • When resistant worms reproduce, they create more resistant worms. Logical and bad. But there is a segment of the worm population known as refugia. Refugia just mean the number of worms that don’t contact a dewormer when one is given.
  • Suppose you deworm your horse. There might be worms in the encysted stage of their life cycle in your horse’s gut. Those encysted buggers are in refugia. So are the worms that are still in egg form in your pasture. So are the worms that live in your barn mate’s horse in the next paddock over who did not deworm.
  • So now the worm population is a two-parter – the resistant ones, and the ones that are in refugia. We need the non-resistant worms from the refugia population to continue to reproduce with the resistant worms to dilute the resistance.
  • Imagine a scenario where every single non-resistant worm was eradicated. This could be on a farm level, a state level, or even larger. The only worms left are the resistant ones. You would be out of luck with any dewormer, and the populations could increase so greatly that horses are at risk of the complications of worms – colic, impactions, etc.
  • Most adult horses now have parasite loads that exist, but do not pose an immediate threat to the health of your horse. But if only resistant worms are left, those loads become harmful.

How to deworm a horse

Lots of dewormers create lots of confusion. Your vet and some fecal egg counts can make things easier to manage.

Now the fecal egg count (FEC) enters the picture.

  • The fecal egg count test tells you and your veterinarian how many eggs per gram (EPG) your horse is shedding via his manure. It’s not an indication of how many actual worms he has.
  • Horses are classified into high, medium, and low shedders depending on their FEC results. Generally speaking, low shedders have less than 200 EPG. Medium shedders are somewhere around 200-500 EPG and high shedders are over 500 EPG.

How to deworm a horse

Pick wisely, with the help of your vet!

Fecal egg counts are not intended to replace deworming but should be a guide to indicate when to deworm and which horses to deworm.

  • It’s recommended practice to take a horse population as a whole on a farm or boarding facility and deworm the high and medium shedders. These horses shed so many eggs that the life cycles of the worms are fast and furious.
  • Most low shedders can remain as is.
  • It’s prudent to do a fecal egg count in the spring and fall, and ideally, all horses on the property should be tested to get an idea of the herd status.

Why doesn’t rotational deworming work?

  • Rotational deworming is when you give your horse a dewormer on a set schedule. I have heard that many people do this every 6 or 8 weeks, or every few months. Again – this is not recognized by the AAEP as an effective way to take care of your horse, and may, in fact, be harmful.
  • This overuse of medications to horses that may not need it is the perfect storm for creating resistance to dewormers.
  • It’s precisely this random dosing of meds that leads to anthelmintic resistance. Remember – there are NO NEW DRUGS on the horizon if all worms become resistant.

When you follow a rotational program without fecal egg tests, you are shooting in the dark.

  • You have no way of knowing what your horse’s parasite load is. And you have no idea if what you are giving is correct for that stage of his intestinal parasite’s life cycle. And you have no idea if it even works.
  • The only ways to monitor your horse’s parasite load are to do a FEC. Then, based on his status as a shedder (high, medium, or low), target his worm population.
  • About 2 weeks later, perform another FEC, this time it’s called a fecal egg count reduction test (FECRT) and the results will tell you and your Vet are on the right track with the dewormer that you used.

Time to stop rotational deworming and stick to the fecal egg count!

How to deworm a horse

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You can actually do a mail order fecal egg count.