Q. On a recent ranch tour, we saw some horses the owners called nurse mares. They said these mares are kept on standby for taking care of any orphaned foals, so they grow up normally without behavior problems. Is the nurse mare just a babysitter/­companion or does it also feed the foal? If that is the case, why would a mare randomly have milk when you need it to feed a foal? What sort of behavior problems would an orphan foal develop?

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A. While very few foals become orphans (I would estimate less than one percent of all foals born), it can occur when the dam is incapacitated or unavailable. In addition to death or illness, a mare might not produce sufficient milk, although this is rare. Also rare is inadequate maternal behavior that might result in an orphan.

For example, a mare can fail to bond with and care for her foal or she might be uncomfortable nursing due to an udder problem (see page 39 in the December 2012 issue). Sometimes a first-time mother is actually afraid of the foal, as if he were a strange species she has never seen before, much like a horse might react to seeing a pig or a llama for the first time. In some cases the mare can overcome these issues and remain with her foal. In extremely rare cases, a mare might attack or "savage" her foal as if he were a small predator. In this circumstance veterinarians recommend splitting the pair immediately for the foal’s survival