Ask the Vet: Foals

Answered by, Madison Seamans, DVM, MS, Kuna, ID Courtesy of AAEP

Question: I have a one-month-old foal and would like to know which dewormer would be safe to use for their age?

Answer: Parasite control has changed dramatically over the recent few years. There was a time when treatment for intestinal parasites involved toxic chemicals that could only be administered by a stomach tube. The advent of over-the-counter “paste dewormers” provided horse owners access to safe and effective treatments they could give without veterinary assistance. Unfortunately, there is a lot of parasite resistance to most of the available compounds, so they are not as effective as they once were. It is encouraging, though, that studies show adult horses demonstrate a high degree of natural immunity against intestinal parasites, over 80%, in some populations.

Good housekeeping, daily stall cleaning and composting manure, will keep parasite populations low. Most important, is to test both the mare and foal and treat only those individuals shedding parasite eggs. Judicious use of the drugs designed to kill intestinal parasites will help control rates of infestation and limit the development of resistance in these disease-causing organisms.

Question: What effect does chia seeds have on foals?

Answer: There are anecdotal reports of some weight loss in people eating chia seeds from the Salvia plant, a type of mint from South America. Seeds from this genus of plant appear in the diets of many indigenous people in the western hemisphere and extracts of it are used in some traditional Chinese medicines. Chia seeds are a good source of omega-3 fatty acids, as are flax and other whole seeds, but there are no controlled studies about their effects on foals. As the mare’s milk is the perfect diet for a foal, supplementation with chia seeds is probably not beneficial.

Question: Is there a risk if foals have access to salt blocks? I have heard that they can become “addicted” to the salt and if they eat too much and die from it. I have also heard that their kidneys cannot cope with the salt until they are six months old. Is this true?

Answer: The use of dietary supplements of any kind, including salt, is somewhat controversial. Mare’s milk contains all the nutrients, including minerals like sodium and chloride (the elements that make up salt) necessary for a growing foal. So a salt block for a foal is probably not necessary. Many mares will have access to a salt block, so if the mare is licking the salt block, the foal probably will, too. True “salt toxicity” is actually due to water deprivation, so it would be very rare for salt to become toxic as long as the horses have access to free choice water.

The foal’s internal organs undergo remarkable changes immediately after birth. Heart, lung, liver and kidney complete an amazing transition from the pre-natal life, when the maternal system takes care of everything, to post-natal life, where the foal’s body must function on its own. In a normal foal, the competency of the kidney should be established by the first few hours of life, and thus.