Parasite Control Linked to Good Health in Horses

Internal parasites are the greatest single cause of colic in horses and are often a contributing factor in many respiratory, digestive and performance problems. Though parasites are a constant problem for horse owners, the severity of the problem can be lessened with a regular preventive worming program, formulated by your veterinarian.

The four most common internal parasites found in horses are bots, strongyles, ascarids, and pinworms.


Bots- are the larvae (immature worms) of the botfly. Since these flies are common to the horse's environment, it is almost impossible for a horse not to be infected.


Strongyles- these infective larvae migrate onto grass blades, where they remain until grazing horses ingest them. Horses with strongyles may lose condition, weaken and have diarrhea.


Ascarids (large roundworms)- affect young horses more than mature ones. Problems such as colic, coughing, diarrhea and small intestinal problems might result from ascarid infection.


Pinworms- though less dangerous than other internal parasites, pinworms are annoying to the horse because they cause severe anal itching.


An effective parasite control program involves each and every animal on the farm. Ideally, intensive treatments should be scheduled at regular intervals from birth on, for the entire life of the animal. We're here to help provide your horse with good health and quality of life. Consult our doctors to help you establish a program that will be practical for your individual situation.