What is a baby horse called?

A foal is an equine up to one year old; this term is used mainly for horses, but can be used for donkeys. More specific terms are colt for a male foal and filly for a female foal, and are used until the horse is three or four. When the foal is nursing from its dam (mother), it may also be called a "suckling". After it has been weaned from its dam, it may be called a "weanling". When a mare is pregnant, she is said to be "in foal". When the mare gives birth, she is "foaling", and the impending birth is usually stated as "to foal". A newborn horse is "foaled".