Deworming schedules are generally aimed at when the drugs will do the most good, eradicating worms before they pass eggs to re-contaminate pastures. In the north, horses are turned out to pasture in spring. “Horses should be treated at least 4 or 5 days before turnout,” says Dr. Craig Reinemeyer (President, East Tennessee Clinical Research, Inc.) because parasites must return to the environment between successive generations.

How to keep your horse safe and healthy when trailering.

Most medications and dewormers are given in dosages according to body weight. Knowing a horse's weight is crucial for estimating proper dosage. Some people can guess a horse’s weight fairly accurately by visual observation, but many horses will fool the guesser. A tall, lean horse may weigh less than a short, stocky one. Body condition can also make a difference. Your horse may weigh 1,200 pounds when he is fat and soft, but only 1,100 pounds when he has been working hard all summer.

Bute is a non-steroidal anti-inflammatory similar to aspirin, Advil, Motrin, Banamine, etc. Bute has been used for decades in horses to relieve pain, particularly in musculoskeletal injuries, navicular syndrome, arthritis, and so on. Melinda Freckleton, DVM (Haymarket, Virginia) says this is a drug that’s used frequently and is a comparatively safe and effective way to reduce pain and inflammation.