Why should horse owners have fecal egg counts performed on their horses?

  1. To help slow resistance development of dewormers.
  2. To determine how effective their horses’ worm control program is working.
  3. To determine what worms are active in their horses’ environment.
  4. To determine which deworming medications work best for their horses,
  5. To determine which horses are low, medium and high contaminators (shedders of eggs) of their pastures.
  6. To determine if they already have major resistance to the deworming medications they use on their farm or stable.
  7. To determine if other worm control practices may be better than deworming at controlling worms in their horses.
  8. To protect their horses from the harmful effects of worms.

Harmful Effects of Worms
There are many harmful effects caused by a horse having worms.  These harmful effects vary according to the species of worms that are present.  Unless the worm infection is severe these harmful effects are not generally seen; however, over time much damage can be done to the horse physically.
Dr. Craig R. Reinemeyer and Dr. Martin K. Nielsen state in their book EQUINE PARASITE CONTROL, “Fecal egg counts remain the cornerstone of equine diagnostic parasitology.”
Here is a list of harmful effects that worms can cause in a horse.  They may differ depending on the worms present, age of the horse, how heavily infected they are, and duration of infection.

  1. Colic
  2. Weight loss
  3. Diarrhea
  4. Stunting
  5. Poor hair coat
  6. Chronic cough
  7. Runny nose
  8. Depression
  9. Poor appetite
  10. Ulcers in stomach
  11. Ulcers in large intestine
  12. Ulcers in small intestine
  13. Ulcers on skin
  14. Tail rubbing
  15. Death