Dewormer- Horses typically get worms when turned out with previously infected horses or when they are turned out in a contaminated pasture. In both situations, it is highly likely the horse will become infected, as well. Pastures become contaminated with the eggs and larvae or parasitic worms through the manure of an infected horse’s manure which then mixes in the grass of the pasture. As your horse grazes, the eggs and larvae are ingested. A pasture can stay infected for a considerable amount of time so always keep the threat of horse worms in mind. Traditionally, veterinarians recommend worming your horse every two months. However, there is a lively debate about the effectiveness of repeated use of the same wormers. Before beginning a worming schedule, it is wide to have a serious discussion with your vet about the best possible worming schedule for your horse. Here are some factors to consider when determining which dewormer to use: Your horse's age. A fecal egg count reduction test performed by your vet. Even if your horse is stabled, it is still susceptible to worms. Only use the drugs that are necessary to kill the worms that are detected in the fecal egg count reduction test. Overexposing worms to dewormers can cause them to become resistant after awhile. Try to use the weather and climate to your benefit. Different climates can affect parasite reproduction which in turn reduces the frequency of deworming. Be sure to follow dosage directions. If your horse does not consume the entire suggested dosage, you’re under dosing him, which is less effective on the parasites. If you have any questions on designing a horse worming schedule, please contact your veterinarian.