Age of Your Pet in Human Years

By: Heidi Lobprise, DVM, DAVDC

TVMA Member
Flower Mound, TX

Published December 2016

Taking the best care of our pets involves routine wellness examinations and preventive care. Most of us are aware of the importance of regular vaccinations, heartworm and intestinal parasite tests and preventatives, as well as dental care to keep them in top shape.

As pets age, veterinarians may recommend additional care and examinations to identify problems and diseases before they get severe. Many veterinary practices encourage senior care programs that include more regular physical examinations (twice a year) and diagnostic work (blood work, urine tests and X-rays) to monitor your pet’s health. Many of these programs start when a pet turns 7 years old. If you estimate a pet’s age relative to humans at seven times its calendar age, a pet begins the program when they are about 50 years old.

While this age comparison works fairly well for medium-sized dogs, there is actually a wide variation in the anticipated lifespan of dogs, depending on their size and weight. Small breed dogs have a much longer lifespan, and giant breeds such as Great Danes may be considered senior at 5 years of age with an average lifespan of 8 to 9 years.

The American Animal Hospital Association (AAHA) Canine Life Stage Guidelines and Senior Care Guidelines set some definitions for your how quickly your dog ages. If you divide a pet’s expected lifespan based on the breed into four equal amounts, “mature” is defined from the middle 50th percentile (middle-aged) to the last 75th percentile. “Senior” is defined as anything above the 75th percentile. For a particular breed with an expected lifespan, this is easier to determine. Other guidelines work to determine their “relative” age and corresponding life stage, based on factors such as the size or weight of a dog

One such chart was developed by Virbac Animal Health and shows the stepwise progression of life stages based on weight categories. Dogs in the 0- to 20-pound range reach their senior designation at 9 years of age; this is 52 years in human terms. The geriatric level is reached at 14 years, which is equivalent to 72 human years. The dog weighing between 21 to 50 pounds turns senior at age 8 and geriatric at age 13. Dogs in the 51- to 90-pound range become senior between the ages of 7 to 11, and dogs that are more than 90 pounds earn the senior title at 6 to 9 years of age. Cats have less variation in size, so the guidelines set by the American Association of Feline Practitioners define mature as 7 years of age, senior at 11 years of age and geriatric at 15 years of age.

These are general guidelines that help determine the relative age and life stage of your pet. Each individual has varying health care needs, so it is important to provide regular preventive care and examinations for your pet with your veterinary team’s assistance. Following their recommendations through these life stages can help optimize your pet’s health.

Dr. Heidi Lobprise, DAVDC (Diplomate, American Veterinary Dental College), practices dental specialty at Main Street Veterinary Hospital.