Final answer:
Heels wear first in horses due to a narrower hoof wall at the heel, whether the horse is barefoot or wearing shoes.
Step-by-step explanation:
In horses, heels wear first whether the horse is barefoot or wearing shoes due to a narrower hoof wall at the heel. When horses walk or run, the weight is predominantly carried on the back of the foot, which puts more pressure on the heel area. This constant pressure on the narrow hoof wall can lead to wear and lameness.Another factor that can contribute to heel wear is improper shoeing. If the shoes are not fitted correctly or if they are not balanced properly, it can cause uneven wear on the heels. Inadequate moisture or lack of moisture can also play a role in heel wear. The moisture helps to maintain the integrity of the hoof wall and prevent excessive wear.Therefore, the correct answer is a) Narrower hoof wall at the heel.