Controlling horse parasites

By Gary Sliworsky

Ag. Rep.

Following is the latest Horse News and Views which is prepared by Dr. Bob Wright, Animal Health and Welfare, OMAFRA, in cooperation with the staff and researchers of the University of Guelph.

The monthly column highlights research topics, extension resources, reminders of common poisonings, disease or production concerns and coming events and is placed on our website, http://www.omafra.gov.on.ca/english/livestock/horses/news.html.

Diatomaceous earth is being promoted as a product capable of controlling internal parasites of horses. The theory that its sharp edges will cut the parasites, and thereby kill them, has a number of flaws. Besides potentially having some adverse side effects, it also gives horse owners a false sense of security. Horse owners should develop a good working relationship with their veterinarian and design a parasite prevention program that incorporates pasture management and regular fecal analysis, with strategic deworming, using the appropriate dewormer given at the right time of year to the appropriate individual horses.

In many parts of the country, the long, dry summer resulted in poor pastures by mid summer and the feeding of hay starting in early August. Pastures have “greened-up” over the past few weeks.

However, don’t expect that there will be sufficient forage to meet the needs of horses this late in the season. Monitor the body condition score of all horses but especially those of mares that raised a foal this summer, older horses with teeth and chewing issues and young horses (weaned foals, yearlings and 2-year olds). Most pastures, this past summer/fall, probably did not meet their nutritional needs. For more information on Body Condition Scoring of Horses refer to www.omafra.gov.on.ca/english/livestock/horses/facts/98-101.htm

The majority of nutrients from hay are extracted by bacterial fermentation in the hindgut (cecum and colon) of the horse. The poorer the quality of the hay, the more hay that needs to be consumed to meet a horse’s daily nutrient requirements. A “hay belly” is a distension of the abdominal area, resulting from consumption of a large volume of poor-quality hay along with water to aid in the fermentation process. A “hay belly” is not a buildup of body fat. (Personal communication - Marc André Blouin, Agribrands Purina Canada)

For further information, contact Dr. Bob Wright (519) 846-3412 or visit our website: http://www.omafra.gov.on.ca/english/