Ways in which dogs age are by slowing down, becoming gray in the face or muzzle and developing some muscle atrophy. Some dogs experience hearing loss and eyes that are cloudy or bluish. Larger-breed dogs age more quickly than their smaller counterparts.
Aging dogs that have cloudy or bluish eyes, an effect called lenticular sclerosis, are not going blind, nor are they developing cataracts. Lenticular sclerosis does not seem to affect vision, but if cataracts, which are white and filmy, develop, the dog should see a vet.
A dog slows down in various ways. For example, arthritis, particularly in large breeds, can cause a dog to walk stiffly and be slower in getting up and ascending steps. Medications can help with arthritis discomfort. Hypothyroidism is another way in which an aging dog may slow down, and the condition is fairly simple to treat with proper veterinary care.
Dogs may begin going gray at middle age, which is 4 to 5 years. Large dogs, such as Great Danes, become seniors at 6 or 7 years old, while toy poodles and other small breeds become seniors in their teens.
Shield dogs that are experiencing hearing loss from possible dangers such as oncoming cars they no longer hear. Hand signals instead of verbal commands can compensate for some of the loss.