Gray hair, stiff joints, poor teeth, and weight changes are not just signs of aging in humans; they afflict horses as well.

Molly Nicodemus, MS, PhD, an associate professor of animal and dairy sciences at Mississippi State University, said horses often display noticeable signs of aging. Although they vary from horse to horse, these indicators can appear as early as 15 years of age.

Nicodemus said owners might notice graying hair, loss of muscle tone, and stiffness in their horses.

"There also may be major changes in weight that can be quite alarming," she said. "The drastic change in weight or the loss of muscle tone makes most owners fearful that something is really wrong