Worming Horses: Facts You Need To Know Now!

Worming horses today can be a real challenge.

With all the different brands on the market, it’s hard to decide which one is right for your horse.

Before you choose which brand to use, it is important to know what you’re dealing with. You can't win the war if you don’t know the enemy.

Worms in horses are a continual threat throughout a horse's life. The damage caused to horses by parasites can be devastating if not prevented. Although, wiping them out completely is probably unrealistic, you can keep them in check.

There are many different types of parasites that reside in our horse’s environment.They depend largely on what region of the country that you live in.

Here is some information about the most common parasites, from life-threatening, to simply irritating. After reading this you will know why worming horses is so important.

Ascarids or Roundworms

Their life-cycle lasts about 3 months. Adult ascarids can be up to 20 inches long, ½ inch in diameter and are bright white. They travel to the horse’s lung as soon as possible. This can cause severe problems, even death if not treated. This is especially true for younger horses.

Signs of ascarids in horses include a pot-bellied appearance, dry cough, diarrhea, poor appearance or dull coat. Respitory infections and pneumonia are also common in infested foals.

Ascarids pass through the manure to grass and the eggs can actually live outside the horse for up to 10 years. Eggs are then ingested by the horse while grazing. Female ascarids can lay up to 200,000 eggs per day. Imagine how many worms your horse could have with a regular horse worming program.

These are considered the most common parasites. Their life-cycle lasts about three weeks. Adult small strongyles can be ½ to 2 inches in diameter and are bright red in appearance.

Small strongyles can be very severe, due to prolific egg laying. Even though the larvae are smaller than the head of a pin. Horses with low immunity and very young horses are especially vulnerable.

Adults lay eggs that are passed out with the manure. There they mature and infest the horse when the grass is eaten.

Some signs of small strongyles are weight loss, decreased appetite and a dull hair coat. They are also a major cause of many types of colic. It has been estimated that 90% of colic cases are caused by worm infestation or damage from previous infestations. Worming horses on a regular basis will alleviate this problem.

Large Strongyles or Bloodworms

These parasites can affect horses of all ages. They are reddish-brown in color and can range from ½ to 2 inches long.

The good news about large strongyles is that, nearly all de-wormers attack them, making them much easier to control. However, if unprotected, horses can suffer sudden death from an infestation.

Large strongyles migrate through the blood vessels and will affect the liver, arteries, pancreas and intestinal walls.

Colic is one of the most common symptoms of large strongyles. Weight loss, loss of appetite and a dull coat are also good indicators.

Always check the label to make sure when worming horses, that your controlling all the possibilities.

Tapeworms

Are yellowish-green in color and are approximately 3 inches long. They can also be a cause of colic in horses.

These worms locate the opening in the colon and then migrate into the large and small intestines. There they sap the nutrients from feed which leads to decreased intestinal mobility. To make it worse, there are hardly any outward signs or symptoms of tapeworms.

Bots

Are the larvae of the bot fly and are bright yellow in appearance. They lay there eggs on the horse’s legs and coat. When the horse licks or bites at his legs, the bots are ingested.

Bots burrow into the tongue and mouth and cause irritation and inflammation. Eventually they work their way to the stomach causing the same symptoms there.

There they remain for 8 to 10 months until the larvae is excreted in manure. They burrow into the ground and emerge as adult bot flies. Worming horses can stop these critters before they have a chance to come out.

Bot eggs should be removed from your horse as soon as possible, to avoid infestation. You can use a bot knife to scrape off the eggs. This should be a regular part of your horse grooming when bot flies are active. Avoid scraping the bot eggs off in places where your horse eats or he could still ingest the bots that you scrape off.

Pinworms

Are brown or dark gray in color. Female pinworms are 3 to 6 inches long. Males are only about ½ long. They have a life-cycle of about five months.

Pinworms are more of an annoyance that a hazard. They travel through the digestive tract to the tail-head region. These little nuisances travel out of the anus and lay their eggs on the surrounding areas. This can cause intense tail irritation and tail rubbing. Tail rubbing, due to intense itching, can then lead to a secondary infection if allowed to continue.

A fecal test should be performed by your vet at least twice a year. This will determine what kind of horse worms you’re dealing with. It will also determine if your horse worming program is doing its job. You may have to re-evaluate your program for de-worming horses.

There are many different types of equine wormers. There are paste wormers, pelleted wormers, liquid wormer, daily wormer, etc. You just have to figure out which one is right for you and your horse.

Paste wormer is the most commonly used method of worming horses. However, they are developed to target different parasites, and will need to be rotated with other wormers to be effective.

For example, if you use Safe-guard as a regular wormer, you would need to also rotate it with something like Zimecterin Gold. Safe-guard is effective for some parasites, but not all. Zimecterin would cover the parasites that Safe-guard doesn’t.

This also keeps your horse from building up immunities to one certain product. If you use the same product everytime, the parasites will become immune to it. This is just an example, I’m not saying that’s what you should use.

Horse Worming Schedule

Always consult your vet and he will help you come up with a de-worming program suited specifically to your horse and the area in which you live.

A good schedule to follow when worming horses is to de-worm about every two months, year round. At least twice a year use a wormer that is effective against all worms and bots, such as Ivermectin.

It is very important to document everything about your horse care regimen. This will eliminate guesswork and prevent possible overdoses of wormer or horse vaccines. Download your free Horse Care Journal here.

There are two very important times of the year to use a bot wormer. The first is during early spring, before the larvae leave the horse’s stomach. The second is in late fall.

Example of an Adult Worming Schedule

Baby horses, or foals, should be first de-wormed at about 2 months old. Subsequent treatments should be given at 2-month intervals thereafter. It is very important that selected dewormers be effective against ascarids, strongyles, bots and threadworms. When a foal reaches 1 year of age, it should be placed on the same schedule as the adult horses.

Example of Foal Deworming Schedule