Identifying Horse Worms

Gastrointestinal equine parasites, or worms, are persistent threats to your horse’s well-being, and can result in disease or even death. There are several ways your horse’s behavior can alert you to possible worm infestation, and you should consult your vet immediately to perform a fecal examination and blood test.

It’s also a good idea to know what to watch for in your horse’s manure. Here’s a description of the most common worms to watch for, and how to identify them:

Strongyles (blood or red worms) can cause colic, gangrenous enteritis, intestinal stasis and rupture, anemia, weakness, emaciation, and diarrhea. They are small and spidery, and generally appear red when they’ve been feeding on your horse, but they start out as white, and look that way if they haven’t been feeding for a while.

Ascarids (roundworms) can trigger weight loss, stunt a young horse’s growth, give a rough hair coat and/or pot-bellied appearance, and cause lethargy and/or colic. They are long, stringy, and yellowish, and can grow to nearly a foot long.

Tapeworms are a common cause of colic and other intestinal obstructions. Their eggs are housed in segments, which are laid when a segment breaks off.

Bots aren’t worms per se, but they are similar in that they can damage the tissue of a horse’s mouth and intestinal tract, and have been associated with gastric ulcers. Bots are the larval stage of certain flies, and show up in manure at the pupae stage.