Non-Chemical Means of Controlling Internal Parasites in Horses: Pasture & Stable Management


Although vital for controlling parasites, chemical control is actually the less important part of a TOTAL parasite control plan. Since parasites are primarily transferred through manure, manure management in pasture or stable is vital. Here are some suggestions:

• Pick up and dispose of manure from stabled and dry-lotted horses as frequently as possible.

• When possible, use a tub for hay and grain rather than feeding on the ground. This is also important in sandy soils to reduce sand ingestion.

• Horses in growing pastures tend to defecate in certain areas in the pasture (the roughs) and graze in between these (the greens). This is likely an adaptive behavior reducing ingestion of parasite eggs. Keep this in mind given your management of the pasture.

• Harrowing pastures regularly may break up manure piles and expose parasite eggs and larvae to the elements, but may also spread viable eggs out onto the grass so that horses are forced to ingest more parasites. Consider only harrowing horse pastures when the weather is hot and dry during the peak of the summer. Always allow allow several weeks for the parasites to die before putting horses out.

• While eggs may be slow to develop to infective stages in cold weather, they OFTEN DO SURVIVE, awaiting the right conditions. Many parasite eggs survive on snow and ice for the winter and may resume their life cycle in the spring.

• Spreading manure on pastures without first composting it will spread parasite eggs on the pasture and can lead to heavy pasture contamination and re-infestation.

• Composting requires watering (in our climate) and turning of piles. Properly done, composting leads to intense heat production and killing of most parasites. Done properly, composted manure can be returned to the land and greatly benefit it.

• Rotate pastures by allowing other livestock, such as sheep or cattle, to graze them. This interrupts the life cycles of equine parasites. Parasites from these other species are unlikely to affect horses.

• Group horses by age to reduce exposure to certain parasites and maximize the de-worming program geared to that group.

• Keep the number of horses per acre to a minimum to prevent overgrazing and reduce the fecal contamination per acre, or use rotational grazing.

Author: Doug Thal DVM Dipl. ABVP