* Breed: Some breeds are naturally smaller than others. For instance, Miniature Horses can be as small as 34 inches tall, while draft horses can be over 6 feet tall.
* Genetics: Just like with humans, foal size can be influenced by the parents' genetics.
* Nutrition: A well-nourished mare will generally give birth to a larger foal than a malnourished mare.
* Health: Foals born prematurely or with health issues might be smaller than average.
However, a very small foal would be considered a "runt" and likely require extra care. It's important to note that a foal's size at birth is not necessarily indicative of its future size. Some foals may be smaller at birth but grow to be larger than their siblings.
Here's a general idea of foal size at birth:
* Miniature Horses: 15-25 inches tall
* Pony breeds: 28-34 inches tall
* Warmblood and Thoroughbred breeds: 30-36 inches tall
* Draft breeds: 36-40 inches tall
If you're concerned about a foal's size, it's always best to consult a veterinarian.