These growth plates are where the limb produces its bone for growth. If the growth plate produces more bone on one side than the other a deviation occurs. This is corrected by medial or lateral extensions - normally a plastic glue on shoe. However, minor deviations can often be corrected by your own farrier trimming down either laterally or medially to encourage correction of growth.

The causes for these abnormalities are generally due to two factors:

a) Developmental abnormalities, poor position in the uterus as the foal develops, conformational ie its breeding and ligament laxity.
b) environmental abnormality, excessive activity or loading of a limb due to opposite leg lameness

The vet will advise you on the correct strategy or maybe refer you to a specialist veterinary / farriery practice. They deal with these angular corrections on a weekly basis and have all the necessary shoes and equipment for these procedures.

There are also surgery procedures to correct the more radical problems. Such as stapling across the side of the growth plate, which is growing too fast, so the other side can "catch up". Or, stripping the weaker side of the growth plate to excite the bone growth thus straightening it out.

The foal can sometimes be born with its fetlocks touching the floor or a radical deviation. This is fairly common and your vet might advise you to protect its legs with bandages etc. and turn it out in the field. This form of exercise will often correct the problem in as little as a week to ten days.

Of course many of these problems are congenital. If a mare has poor conformation, maybe flat feet and toe out, or an upright boxy foot then clearly don't breed with a stallion that will accentuate the problem. Some would say don't breed it at all, however, carefully select your breeding programme.

Mostly, a youngster will look slightly "base wide". This is not a bad thing, because as it grows and matures its chest will widen, in doing so the top of the limb will rotate and providing the limb has no deviation, the long axes will become more parallel.

Regular visits by your farrier are very important, not only for him to check for any problems, but also to educate your youngster in manners for having its feet done. If any work has to be done it is very difficult if the animals legs are flailing around!. But don't rely on your farrier doing all the breaking in with regards to feet, it's hard enough as it is.