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Deworming Horses

Deworming Horses


How often do you deworm your horses? If you are deworming your horses only twice per year, you may be leaving them vulnerable to the dangerous parasites that infect and breed in even the best cared-for horses.

Equine parasites are always in season, and produce anywhere from 5,000 to 100,000 eggs every day of the year. It can take as long as six months from infection until external signs appear, at which point internal damage may be irreversible. Establishing a regular parasite control program is as important to your horses' health as supplying them with clean, plentiful water and high quality feed.

Choose a Deworming Schedule

Your veterinarian can help you decide the best deworming plan for your horses, depending on their number, age, geography, and pasture management.

Daily Deworming

Administer a daily dose of the deworming agent in your horse's feed. Dosing is based on your horse's weight; it is imperative that you have an accurate weight and that you stay on the program.

Strategic Interval Deworming

Deworming only at certain times of the year or when fecal egg counts rise.

Get Rid of Parasites Before They Become a Problem

Here are some suggestions from the American Association of Equine Practitioners:

  • Pick up and dispose of manure droppings in the pasture at least twice weekly.
  • Mow and harrow pastures regularly to break up manure piles and expose parasite eggs and larvae to the elements.
  • Rotate pastures by allowing other livestock, such as sheep or cattle, to graze them, thereby interrupting the life cycles of parasites.
  • Group horses by age to reduce exposure to certain parasites and maximize the deworming program geared to that group.
  • Keep the number of horses per acre to a minimum to prevent overgrazing and reduce the fecal contamination per acre.
  • Use a feeder for hay and grain rather than feeding on the ground.
  • Remove bot eggs quickly and regularly from the horse's haircoat to prevent ingestion.
  • Consult your veterinarian to set up an effective deworming program for your horse(s) and monitor its effectiveness.

Updated: June 1, 2015