The Age a 7 year old dog is in Human Years

An average sized 7 year old dog is equivalent to 47 year old human.

However small dogs age more slowly, so will be equivalent to a 44 year old human.

A large dog will be equivalent to a 50 year old human.

For the first 5 years all sized dogs age at the same speed.

You want to make sure that your furry friend stays happy and healthy. Sometimes, this involves learning about how dogs’ systems function.

You are probably aware that dogs age much more quickly than humans do. In fact, you have probably heard that as a general rule, a dog ages seven years for every year that passes by. However, it turns out that it’s a little bit more complicated than this.


Larger Dogs Age a Bit Faster

It actually depends on the dog. Specifically, the breed and the size of your dog. Typically, smaller dogs live longer than bigger ones.

When the dog has lived for seven years, the difference isn’t that drastic.

A small dog (20 pounds or less) at this age will be the equivalent of a 44 year old human being,

 A medium-sized dog (21- 50 pounds) will be like a 47 year old human,  

A large dog (over 50 pounds) will be like a 50 year old person.

Of course, these canine ages vary. Even within the same size category, different breeds can age differently.


Younger Dogs Age More Slowly and Then It Gets Faster

Even though you might have heard that one year for your dog is the same as seven years for a human, it’s actually not this straightforward. It turns out that there isn’t a simple linear relationship between dog years and human years.

In fact, if you think about it, it wouldn’t make sense to say that humans just age at a pace seven times slower than that of dogs. Dogs reach sexual maturity and are able to reproduce when they are only one year old. This would mean that human beings would be able to have babies at seven years old and live to be about 150. Obviously, this is not true, so the relationship is a little bit more complex than that.

In actuality, the first year of your dog’s life is the equivalent of about 15 years for a person. This is why most dogs are done growing, or close to done growing, by the end of the first year. Their physical maturity levels are more comparable to that of a human teenager than that of a human seven year old child.

In fact, up until about five years of age, dogs age very similarly, regardless of their size. After one year, they are equivalent to human 15 year olds. After two years, they are like 24 year olds.

Then, the aging process slows down a little bit, with dogs only aging four more human years for each of the next three years, so that they are like 28 year olds at 3, like 32 year olds at 4, and like 36 year olds at 5.

After this point is when size starts to matter in the canine aging process. This is why by the time a dog is seven years old, there is a slight difference in biological age between dogs of different sizes.

When dogs get even older than this, the difference in speed of the aging process is less pronounced.

The bigger dogs are going to age at a significantly faster pace after this, compared to the smaller ones.

By 16 years of age, while a small dog will be the equivalent of an 80 year old human, a large dog will be the equivalent of a 120 year old human. This is why it is much less likely for a large dog to even live this long.


The Possible Reasons Smaller Dogs Have Longer Lifespans?

Generally, a small dog is considered to be a senior dog at about seven years old. However, a large dog will generally be a senior earlier than this, at about five or six. A well-known large dog is the Great Dane, who has an average life expectancy of about 7 to 10 years.

However, researchers haven’t been able to figure out exactly why this is the case. Most of the time, large mammals, like whales and elephants, have longer lifespans than small ones, such as rodents. It’s somewhat baffling, then, that large dogs tend to age much more quickly than smaller dogs.

In fact, generally, every 4.4 pounds of body mass is thought to reduce a dog’s life expectancy by approximately a month. Though nothing is known for sure, there are a few possibilities that could explain this.

It’s possible that the accelerated growth of the larger dog breeds may put them at higher risk of abnormal cell growth, which can in turn make cancer more likely. Larger dogs also may have a natural tendency to succumb to age-related illnesses more quickly.


Methods to Tell How Old a Dog Is

In some cases, you’re simply not going to know the age of the dog for sure, as in situations where the dog was a rescue and you don’t know his background.


Condition of the dog’s Teeth

Veterinarians will often use a dog’s teeth as a guideline to predict age. However, you should keep in mind that this method isn’t foolproof. The state of a dog’s teeth can vary quite a bit depending on the type of dental care he has had in his life.

Generally by:

  • Eight weeks of age, the dog has all of his baby teeth.
  • Seven months, he has all of his permanent teeth, and they are generally clean and white.
  • At one to two years of age, the teeth have dulled a little bit, and there might be a little bit of yellowing in the back.
  • After three to five years, there might be some wear and tear on the teeth, as well as tartar build-up.
  • At 5-10 years old, the teeth will have more wear and possibly signs of disease
  • At 10-15 years old,  the dog will be a senior dog, its teeth will likely be worn with heavy tartar build-up. At this point, some teeth might be missing as well.


Other signs of a dog’s age

Your veterinarian can perform tests or a complete physical exam that will delve into the state of your dog’s internal organs, as well as his muscles, joints, and bones.

Senior dogs tend to have certain visible signs of aging as well. They have white or gray hair, which starts to become visible around their muzzles and then can spread around their bodies. They can also have loose skin and stiff legs. With some of these dogs, you’ll also see cloudy eyes as they age.


Seeing a dog’s age using DNA analysis technique

Recently, a more scientific way of looking at it has come to light. In 2019, researchers at the University of California – San Diego came up with a new method for calculating the age of a dog. In both people and dogs, DNA molecules acquire methyl groups as the organism ages. This alters the activity of the DNA without changing the DNA itself.

When scientists have studied aging in humans, they have referred to this DNA methylation as an “epigenetic clock.” It turns out that a similar methodology can be applied to dogs.

The research team performed targeted DNA sequencing in 104 Labrador Retrievers of all different ages, from 0 to 16. The formula they came up with involved multiplying the natural logarithm of the dog’s age by 16 and adding 31 in order to come up with their age in human years.

Of course, this is going to vary from dog to dog. However, it is interesting that they were able to come up with such a formula. It certainly points to potential interesting discoveries in the future on this topic.


Now That You Know Your Dog’s True Age…

As a dog owner and a dog lover, you want to know your dogs age in human years to understand how long you can expect to be able to enjoy your dog’s company. Dog lovers want to be able to make sure that they have their beloved furry friends for as long as possible.

Of course, you should keep in mind that the rules that we have presented are just general rules of thumb. There are always exceptions, and there is quite a bit of variation based on the different health issues that tend to affect specific breeds. You may not be able to control how your dog ages completely, but you can extend his life by keeping him as happy and healthy as possible.


Writer: Nilani Thiyagarajah

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