Note: featured image from Amanda Jones’ incredible book Dog Years
We’ve all heard a dog’s age is calculated using the 7-to-1 ratio—seven human years for every dog year. The problem is, it isn’t true! This 1950s generalization was based on the statistic that humans lived to about 70, and dogs to about 10.
Sure, dogs age faster than humans, but a variety of factors play a part. Things like size, breed, weight, overall health, and even the food your pet eats all contribute to how fast he ages. In general, every dog years calculator bases its conclusions on a dog’s size, especially after the first two years of a dog’s life.
Dog Years Calculator
The American Veterinary Medical Association says regardless of size or breed, puppies age the equivalent of 15 human years in their first year of life. Year two is equivalent to roughly nine human years. Then, it starts to vary.
Want to know your dog’s age in human years? While there’s not a cut-and-dry method to calculate dog years, you can consult this general chart, provided by the American Kennel Club:
Generally, smaller dogs live longer than larger dogs. German evolutionary biologist Cornelia Kraus thinks large dogs might start aging earlier and thus develop age-related illness sooner. Her research also suggests large dogs age at an accelerated rate, as if “their adult life unwinds in fast motion.”
Research also suggests large dogs age at an accelerated rate, as if “their adult life unwinds in fast motion.”
The reasons why large dogs age faster are largely unknown. Scientists hope to come up with some answers through studies like The Dog Aging Project, which focuses on enhancing the healthy period in dogs’ lives to extend their lifespan.
Dog Aging Factors You Can Control
Just as health problems can shorten a human’s lifespan, they can also shorten your dog’s life. Some of the more prominent causes of earlier death in our dogs rise from problems such as:
- Obesity and a lack of exercise. More than half our pets are classified as obese and nearly all their owners believe they are at a healthy weight. Aim to get your dog at least 30 minutes of exercise a day. Consult your vet to see if your dog also needs to go on a diet. Supplementation for joint, bone, and skin health can also help.
- Poor dental health. Roughly 90% of dogs have some level of dental disease by age 3. Regularly brushing your dog’s teeth can sharply reduce the odds of a severe infection. Regular check-ups and cleanings are also a must.
- Lack of flea, tick, and heartworm prevention. Monthly preventatives should be used year-round in some climates. Many pets also have allergies to fleas, so preventatives are a must! Heartworm treatment is costly and involved, so be sure to protect your dog with a much cheaper preventative if you live in an area prone to it.
- Cancer. Cancer now sadly accounts for nearly 50% of deaths in dogs aged 10 or older. Feeding quality foods without chemicals and preservatives may help reduce the risk of cancer.
Here are some of Canine Journal’s most common dog health issues, many of which are preventable or treatable:
As pets enter the senior stage of life, they’ll need more frequent vet visits to address age-related illnesses. Heart, liver, and kidney disease, as well as cancer and arthritis, are common in aging dogs.
The Bottom Line
If you’re wondering how to calculate your dog’s age in human years, there are a few general methods to follow. And if you’re hoping to prolong his lifespan, make sure he leads a healthy, active life to not only increase his life, but also the number of quality years he lives.