Reader's Question: How much salt does the average horse need per day? I quit giving my two horses a salt block because it was gone in a few days--they ate it like candy. I want to add loose salt to their daily feed, but I'm not sure how much to give them. I assume it depends on their size and activity level.
Dr. Hintz: You are correct in assuming that the need for sodium and cloride, which together make salt, varies with the horse's activity, size and environment. Any factor that influences the amount a horse sweats also influences his need for salt.
The National Research Council suggests that horses at rest need only 25 grams of sodium cloride per day. However, other researchers have concluded that heavy work could increase the sodium requirement eight- or ninefold, which would necessitate providing 200 grams of sodium cloride or more in the diet or with electrolyte solutions.
If your horses perform a modest level of work, they might need about 55 to 65 grams of sodium cloride per day, which is about four teaspoons of table salt. However, there is probably already salt in their grain mix, so check the nutrient contents on the label to determine just how much more you'll need to provide.
Harold Hintz, PhD, is a nutritionist at Cornell University in Ithaca, N.Y.
This article first appeared in the December 2000 issue of EQUUS magazine.