How Old Is My Dog? Calculating Your Dog’s Age in “Human Years”

By Mary Kearl

How do dog years correspond to people years? The rule of taking your dog’s age and multiplying by seven doesn’t always work!

As pet parents, we want the best for our dogs, especially when it comes to helping them age in good health—so that their golden years may truly be golden. Part of that is having an understanding of how old your dog is in terms of their own lifespan. What stage of life a dog is in will affect the type and level of care they need.

Dog Years vs. Human Years

Just how do dog years correspond to our own? Though it’s treated as common knowledge, the rule of taking your dog’s age and multiplying it by seven isn’t quite accurate. For starters, it doesn’t take into account the range of canine breeds and sizes or factor in the difference in how early in life dogs hit puberty compared to humans. Research indicates that before age 1, the aging process in dogs can be as much as 20 times faster than that of humans. Later in life this ratio is about 5:1.

Citing The Journals of Gerontology, The Wall Street Journal reported that by age 1 a Miniature Poodle is about 10.9 in human years, whereas a Great Dane is 26.8 in human years.

Instead of multiplying your pet’s age by seven, some suggest following this rule: for small-breed dogs (10-15 pounds), which tend to live longer, multiply the animal’s age by six to find the human equivalent. For larger dogs, with generally shorter life expectancies than smaller canines, multiply the age by eight.

How to Tell If a Dog Is a Senior

There is no clinically defined age for the start of the last phase of a dog’s life, but a good rule of thumb is to think of this stage’s duration as equivalent in years to the last quarter of your dog’s lifespan. So for larger dogs, that will usually be from age 7 to 10 and for smaller pooches that could be from about 14 to 18. Generally, when your dog is in this stage in life, it’s recommended to start offering a senior dog diet.

Signs of Aging Can Include:

White or gray hair around the face
Taking more time to do things, like waking up and getting out of bed
A drop in energy level and interest in play
Difficulty seeing and hearing, which may make your pet less responsive to your attention or commands
Cloudy eyes
Weight changes
Trouble getting on and off furniture or in and out of cars
Irritability around children and other dogs
Having to go potty more often, including not being able to hold it through the night
Incontinence
Lower tolerance to extreme temperatures and weather

Healthy, Happy Golden Years

In healthy dogs, these changes should be gradual. Senior dogs generally have stable habits, so any jarring deviation from the routine–be it related to behavior, activity, weight, diet, or elimination–could signal a health issue that needs immediate attention from a veterinarian. It’s recommended to take older dogs to the veterinarian twice a year, and any time your notice changes in their habits. Daily tooth brushing is advised at all ages to combat dental disease, which can cause infection in the mouth, that can spread to the heart and kidneys.

Common aging-related health issues in dogs include those related to the intestines, kidneys, liver, prostate, brain and joints, as well as breast cancer, testicular cancer, arthritis and diabetes.

Seek Medical Care If You Observe:

Incontinence
Lumps
Constipation or diarrhea
Vomiting or loss of appetite
Difficulty breathing
Coughing
Weakness
Unexplained weight fluctuations
A change in urination or drinking
Stiffness or limping
More barking, whining, or growling
An increase in aggression or irritability
Drastic change in behavior
Discharge of the eyes or ears