Cats and small dogs are generally considered "senior" at seven years old, but we all know they've got plenty of life left in them at that age. Larger-breed dogs tend to have shorter life spans compared to smaller breeds and are often considered senior when they are 5 to 6 years of age. The "senior" classification is based on the fact that pets age faster than people, and veterinarians start seeing more age-related problems in these pets. Contrary to popular belief, dogs do not age at a rate of 7 human years for each year in dog years.
While it's easy to spot the outward signs of aging, such as a graying coat and slower pace, it's important to remember a pet's organ systems are also changing as they age. An older pet is more likely to develop diseases such as heart, kidney and liver disease, cancer, or arthritis. Cancer accounts for almost half of the deaths of pets over 10 years of age. Dogs get cancer at roughly the same rate as humans, while cats have a somewhat lower rate.
It is normal for pets to lose some of their sight and hearing as they age, similar to humans. Older pets may develop cataracts. Pets with poor sight or even blindness can get around well in familiar environments. If your pet's eyesight is failing, avoid rearranging or adding furniture or other items that could become obstacles.
If your pet is starting to avoid active playing or running or if it has trouble with daily activities such as jumping up on its favorite chair or into the family car, it may have arthritis. A pet with arthritis may also show irritation when you touch or pet it (especially over the arthritic areas), and may seem more depressed or grouchy. There may be other reasons for these changes; you should have your pet examined by your veterinarian to determine the cause of the problems.
Behavior changes in your pet can serve as the first indicators of aging or of a problem. These changes might be due to discomfort or pain (arthritis, etc) or worsening sight or hearing, but they may also be due to the normal aging process. Some behavior changes in older pets may be due to cognitive dysfunction, which is similar to senility in people.
Weight can have a tremendous effect on an older pet's health. Excess weight on an older pet increases the risk of arthritis, difficulty breathing, insulin resistance or diabetes, heart disease, high blood pressure, skin problems, cancer and other conditions. An overweight pet may not show any early warning signs of health problems, so regular visits to your veterinarian are recommended. Sudden weight loss in an older pet is also a source for concern, especially in cats. Hyperthyroidism (an overactive thyroid gland), diabetes and kidney disease are common causes of weight loss in senior cats. If you notice any sudden changes in your older pet's weight, contact your veterinarian.
Because senior pets are more likely to develop age-related problems, they should be regularly examined by a veterinarian to keep them healthy and to detect problems early, before they become more difficult and costly to treat. Talk to your veterinarian about a preventive care schedule that best suits your pet.
The content on this page is a condensed version of our brochure, Senior Pets, available in English and Spanish.