Posts Tagged ‘roundworms’

Equine Parasites (Worms)

Types of Worms, How your horse can get them, and how to control them…..


continuing on the subject of horses pest problems and the horse treatments and remedies you can use to combat these problems I would today like to talk to you about worms.


Worms are a constant problem for Horse Owners, they are the single most common cause of colic and many other digestive and performance problems.


They can be controlled with a regular worming program, but to best prevent them you need to know what they are, how they are contracted, and how to recognize them, as well as how to treat them most effectively.


First I am going to talk about each of the different types of internal parasites or worms, then later I will tell you in detail how to go about treating and preventing them…….this will be a very long article, but one which will I hope be useful to anyone who owns or breeds horses.


The four most common types of internal parasites are Ascarids, Strongyles, Tapeworms and Bots.


Ascarids (roundworms)

These are most common in younger horses, from a few weeks to about 2 years old.


They can be several hundreds in number inside the horses gut, measuring between 6-12 inches each, and will cause colic, coughing and diarrhea.


Their eggs are passed on through the feces and digested by other horses in contaminated hay or water. The larvae then burrow through the gut wall and migrate through internal organs for several months causing irritation and damage. They then return to the gut to mature and lay more eggs to be passed on through the feces again.


Strongyles (bloodworms)

These can affect horses of all ages, they should be taken very seriously because they migrate through the blood vessels in the intestine, causing inflammation, pain,  and possible “fatal” colic.


The eggs are passed through the feces of the infected horse, they can then lay dormant for long periods until the right conditions of moisture and warmth hatch them out. The larvae then migrate onto grass blades where they remain until they are ingested by horses eating the grass.  once inside the stomach they migrate through the blood vessels and travel along the walls of the arteries, liver, and intestinal wall, eventually returning to the large intestine as young adults, to lay eggs and start the cycle all over again.


Horses with these worms may become anemic, lose condition, weaken, have diarrhea, and in some cases can die from the rupturing of arterial aneurysms.



There are several different species of tapeworm, varying mainly in size and lifespan. They are typically fairly flat bodied with suckers with which they attach themselves to the internal organs, in particular the instestines.


The eggs of the tapeworm are passed in the feces of the infected horse and are then consumed by soil mites, which are in turn consumed by horses.


The larvae develop into adult worms in the horse’s gut. Adults live in the ileo-caecal junction of the gut where they attach to the gut wall by hooks. They cause inflammation which in conjunction with reduced gut motility can lead to an increased risk of gut obstruction or even rupture.


Aside from the usual clinical signs of parasites ( rough haircoat, lethargy, loss of appetite, diarrhea), it is very difficult to diagnose tapeworm infection.  This is because the parasites do not lay eggs that can be easily detected by examining a fecal sample.  Eggs present in the feces are the result of a ruptured proglottid.


Tapeworms are usually viewed as benign when compared with some of the other parasites.  However, heavy infections can result in cecal hemorrhaging, blockage, ulcers,  and perforation of the gut.



Bots are the larvae of the Bot or Warble fly, since these flies are extremely common in the horses environment they are almost impossible to avoid.


Bots or Warbles Adult flies lay yellow coloured eggs on the chest, forelegs, throat and nose of the horse. When the horse grooms, the eggs are picked up in and around the mouth. The larvae hatch and migrate to the stomach, attaching to the stomach lining causing irritation,  and gut obstruction. After 8-10 months they are passed in the faeces, they then burrow into the ground to pupate.  Bot or warble flies emerge from the ground and so the cycle continues.


Now that you know a little about the different types of worms and their affects on your horses health I want to talk more about how to diagnose and treat horses which are infected, and also how to put a preventative worming program into action and thus try to avoid future infections.


Since this post is very long already I will cut off now and continue in a new post. (Diagnosing and Treating Worm Infections in Horses)


Technorati Tags: ascarids, bloodworms, bots, equine parasites, horse treatments and remedies, horses, horses pest problems, roundworms, strongyles, tapeworms, worms

Page optimized by WP Minify WordPress Plugin