Bone loss: Dogs undergo a decrease in bone density, but they tend not to develop osteoporosis. Dogs do experience fractures but not because of decreased bone density throughout the body, like in older people.
Neurologic decline: Falloff in this area divides into two categories: a decline of the senses, including smell, sight, and hearing; and a decline in the function of brain cells. The longer dogs live, the more important it is to watch for signs of the canine version of Alzheimer’s, because the earlier it is detected, the more treatable it will be.
Nicholas Dodman, BVMS, is a world-renowned animal behaviorist and the best-selling author of several books, including The Dog Who Loved Too Much, Dogs Behaving Badly and The Well-Adjusted Dog. He is director of the Animal Behavior Clinic at the Tufts Cummings School of Veterinary Medicine.