Parasite Control
Because they live outdoors and eat from the ground, horses are subject to being robbed of nutrition and having their digestive tract damaged by many different kinds of parasitic worms. Your horse is going to get worms simply because of his environment, but prevention can protect your horse from a major worm infestation that could compromise her health.
Your veterinarian can recommend suitable deworming agents and set you on a schedule. Different parasites thrive in different climates, soil, and conditions, so you should follow a deworming schedule recommended for your area. Many deworming medications are in the same chemical class, but the way they're administered can vary from region to region, depending on the parasitic cycles common to a particular area.
Your vet can have a sample of your horse's manure tested to see what worms are present and select appropriate dewormers accordingly. Most horse owners learn to administer paste dewormers themselves, typically every other month, or as recommended by a vet. Paste dewormers have the consistency of ointment or gel, are flavored to a horse's taste (usually apple or molasses), and typically come in a syringe-like tube applicator. They are easy to administer simply by placing the applicator in the upper corner of the horse's mouth and squeezing the plunger. Your vet can show you how to do this. Some dewormers are available in pellet form so they can be mixed with feed. The major drawback, however, is that many horses won't eat them.
By squeezing the thick layer of skin on the end of the horse's nose with a twitch, you give the horse something else to think about besides that worming medication. Although it looks a bit barbaric, the twitch is used in an area known to be an acupressure point, one that releases natural pain-relieving, soothing endorphins that help the horse relax.
Clean manure out of the horse's area as often as possible. Picking out stalls daily and paddocks once or twice a day is ideal. Fresh manure is the perfect environment for flies to lay their eggs, which, if left in the paddock, can be ingested by the horse.
In larger pastures where horses have plenty of room to move about and graze, they usually avoid eating near the areas where they defecate. These areas, called roughs, must be removed periodically to prevent the field from becoming sour. If you can't remove the droppings by hand, harrow the field at intervals to spread them.
Rotating grazing areas is a good idea if you have enough land to rope off the field in sections with electric tape and move the horses from one section to another. This allows the vacated area to rest and recover from the damage horses do to it. This practice also helps keep parasites in check by encouraging their numbers to die off.
Horses have internal and external parasites. For many, the life cycle is completed in or on the ground, but the host, the horse, is important in at least one or more phases of the process. Preventing internal parasites involves putting the horse on a regular deworming schedule, as recommended by your veterinarian. The choice of medication depends on the types of parasites that are most prevalent in your geographic area. Ivermectin, for example, is a common broad-spectrum paste dewormer, but several others are available. Your veterinarian may recommend rotating medications to avoid resistance, in which parasites build up a tolerance to a certain chemical.
The following are the most problematic internal parasites that affect horses:
Small and large strongyles: These bloodsucking worms attach themselves to the intestine and can cause anemia and ulcers.
Pinworms: These live in the large intestine and cause irritation around the rectum.
Ascarids or roundworms: These can cause coughing, inflammation, and gut problems if the buildup is large.
Tapeworms: Once thought to be relatively uncommon in horses, these pests, when present in large enough numbers, steal nutrients and contribute to anemia, wasting, and colic.
Bots: Bot flies lay tiny yellow eggs on the horse's body, usually the legs. The horse ingests the eggs, which cycle through the body and pass out through the manure, where the fly emerges, and the cycle repeats itself. To prevent these parasites, scrape the eggs off your horse with a bot knife or pumice stone.
Lungworms: Rare in horses but usually associated with donkeys, lungworms live in the lungs.
