What are common signs of aging in dogs?
Therefore, it can be helpful to look at physical and behavior clues to determine your dog’s age. For example, teeth can be a particularly useful indicator of your dog’s age. As PetMD explains, by seven months, all of your dog’s permanent teeth are in; by 1-2 years, they’ll be duller and might have some yellowing; and by 5-10 years, they’ll show wear and possibly signs of disease.
Other indicators of your dog’s age, especially as they reach the senior stage, include:
Of course, you can always turn to your veterinarian for an accurate estimate of your dog’s age if you’re unsure. Your veterinarian will consider factors, including teeth, body shape, hair or fur, and eyes, etc. to give the best estimate of their age.
Note: It is a common belief that 1 human year is equal to 7 dog years. That is not very accurate, since dogs reach adulthood within the first couple of years. The formula used above is from a canine expert and is a bit more accurate. (as accurate as one can judge these things)
How do I calculate my dog’s age in human years?
If you’re looking to calculate your dog’s age in human years more accurately, you can use a new formula created by researchers at the University of California San Diego School of Medicine.
These researchers studied the way human and dog DNA changes over time looking at patterns called methyl groups in humans and Labrador Retrievers. From this research, they concluded that you can calculate a dog’s age to human years by multiplying the natural logarithm of the dog’s age by 16 and adding 31. Their formula looks like this: (human_age = 16ln(dog_age) + 31). As you can see, this formula is pretty complex, so it can be useful to plug in your dog’s age to an automatic calculator programmed with this formula, like the one here.
For an easier (and also accurate) way to estimate your dog’s age, you can follow this methodology for small, medium, and large dogs under 100 lbs.
So, why is this more accurate than the “one dog year equals seven human years” method?
Because it takes into account that not all dogs breeds age the same way. In general, smaller dogs live longer than larger dogs, so while a seven-year-old Great Dane might be considered a “senior” dog, the same isn’t necessarily true for a seven-year-old Chihuahua. Therefore, it’s helpful to break down a dog age chart in terms of size, as you’ll see below. Generally, you can group dogs into small dogs (under 20 lbs), medium dogs (20 to 50 lbs), large dogs (50-100 lbs), and giant dogs (100+ lbs).
Check out the dog age to human age chart below to calculate your dog’s age in human years based on their size group:
As you can see in our dog age chart – aside from the giant category – small, medium, and large dogs age pretty similarly until they reach about age six. Then, larger dogs age much faster in comparison to their smaller and medium counterparts. By seven years old, a small dog, like a Dachshund, will be six human years younger than a large breed, like an Airedale Terrier. Why is this?
Ultimately, scientists aren’t completely sure why smaller dogs age slower and live longer than larger ones. According to the American Kennel Club, some researchers hypothesize that it’s because larger dogs are affected by age-related diseases more quickly. Similarly, larger dogs progress from puppyhood to adulthood much faster, making abnormal cell growth, cancer, and other diseases more likely. It’s for this reason that using the “one dog year equals seven human years” calculation isn’t completely accurate.
While the newer method we’ve shared is more accurate, it’s still difficult to place a general formula on the way dogs age – as this progression will not only depend on your dog’s size, but their breed and individual genetics as well.