Can a yearling be in foal?

there is some differences between younge and old horses in general younge horses can be more fisty, fit ,naughty , playful , dangerous , dumber , and a number off other things as well most lder horses seem to be more tollarent with younge children and animals , and seem to get sick VERY easily they get tired more frequently and cant be worked so hard!hope tis answers your question. and they are more likely to become lame You can also tell the difference between and older horse and a younger horse because the older horses tend to have a dip in their back, and their teeth are more protruding. they also have a little grey lingering here and there. young horses are a little bit more in shape too.