Craig R. Reinemeyer, East Tennessee Clinical Research Inc.

Once or twice a year. Spring, possible second dose in mid- summer.

Spring prevention decreases the entire transmission on the farm because there are no eggs being passed out for the mites to eat, consequently, no infected mites for the horse to ingest. “Concentrate your treatments earlier in the grazing season to prevent build-up in the fall.”

Brady J. Bergin, Oregon State University

One to two times yearly.

“Timing depends on the area. Spring is usually a good time since it follows the wet season when the climate supports parasite maturation.” Horses considered at high risk (a history of a tapeworm infection or colic associated with tapeworms) should be dosed every six months. Horses at low risk (those living in a dry climate with limited access to pasture) can be dosed yearly.

Tom Kennedy, Farnam Companies

Fall and spring.

“Usual treatment periods are in the fall after the infection season with a second treatment in spring to prevent pasture contamination and re-infection of the mite population.”

Robert H. Dressler, Pfizer Animal Health

Fall and spring.

“Depends entirely on the part of the country that you’re in and the climate that year. Program can vary from year to year with changes in the climate—wet year, dry year, et cetera.”

Frank Hurtig, Merial

Two to six times annually. Minimally spring and fall, better with the addition of summer and winter treatments.

“Safety margins support use of tapeworm control products in treatment schedules that follow traditional timing for deworming horses—two to six times per year depending on risk of exposure.”

Kevin Hankins, Fort Dodge Animal Health

Once or twice a year; spring and fall.

In areas of reduced prevalence, once yearly in the fall.