How can you tell how old a dog is? You can estimate

How can you tell how old a dog is? Dogs don’t often come with birth certificates and it’s likely they can’t tell you the exact date of their birth. So, we often just have to guess. Especially if you have a rescue dog with an unknown history. However, there are ways to at least be in the ballpark when determining their age. Here’s how:

Entlebucher-Mountain-Dog-On-White-01Body Shape/Muscles

As dogs age, how their weight is distributed changes. When you run your hand down on either side of her spine, you can see if there are fatty pads that have developed over her lower back and lumbar area. This is the sign of an older dog. Mild muscle wasting, which is a sign of age, will lead to a more prominent spine and sway-backed appearance.

Weight gain can also be a sign of advancing age in dogs.

Also, look for signs of arthritis as this is common in both older dogs and humans.

Eyesclose up of cloudy dog eye

Look into her eyes. Do you see a bit of cloudiness there? That’s a sign of lenticular sclerosis which is an age-related condition that causes the lens to become fuzzy or opaque. It only minimally affects vision. Cataracts on the other hand do impair vision. Your dog’s eyes will appear milky white if she has this condition. Some breeds are more predisposed to this.

As she ages, there may also be some discharge coming from her eyes. This, along with cloudiness, usually develops around 6 to 8 years of age. However, cataracts can even develop at a young age due to congenital disease, diabetes or ocular trauma.

close up of dog furFur Coloring

I’m sure we’ve all seen this – gray hair on dogs; especially around the eyes and muzzle area. Just as with humans, the hair grays or whitens with age. Keep in mind however, that many dogs are born with a lot of white in these areas, or they will become white at a young age. This is especially true for wire-haired breeds. Typically, the graying of the muzzle starts at around 5 years old but it can be younger in some dogs. Some believe that stress can also lead to premature graying (sound familiar?)

HearingBasset hound with ears extended

See how much dogs are like humans! If you’re an older person you may have noticed yourself asking people to repeat things. Well, it’s the same for dogs (although they likely won’t ask you to repeat things)! Dogs have a great sense of hearing but it may be on the decline when you notice they aren’t responding to your voice,

dog riding bikeMobility/Activity Level

You’ll definitely notice when you dog starts to slow down, especially if she’s always been an energetic type. We all slow down as we age and this is just part of life. But hey, now both you and your dog can look forward to relaxing more!

However, do keep an eye out for conditions like osteoarthritis which is a progressive and long-term deterioration of the cartilage surrounding the joints. Older dogs are definitely more at risk for this condition. However, even younger dogs with congenital malformations like hip or elbow dysplasia or a history of trauma, may show signs of arthritis. You can read here about supplements that may help.


According to the Humane Society of the United States, the most reliable way to determine a dog’s age is by examining her teeth. Puppies up to 4 weeks old will likely have no teeth. At 4 to 8 dog with funny smileweeks they will have needle-sharp temporary teeth. After 4 months of age, your dog’s permanent or adult incisors, canines and premolars should be coming in. By six months, the baby teeth should be gone. If there are still a few baby teeth, you can ascertain she’s younger than 6 months.

The permanent teeth will remain clean and bright until about 1 year old. After that, your dog’s teeth might start to show a bit of wear. Initially, you’ll see stains and plaque on the back teeth. At around 3 years, most dog’s teeth will have some yellow and visible plaque. By 5 years old, dogs tend to have lots of tartar and their teeth are less pointed or perhaps slightly worn down. Dogs older than 10 will often have cracked or missing teeth.

Of course, some of this depends on how well you’ve cared for her teeth. Please go to my post on how to clean a dog’s teeth.

Note that smaller dog’s tend to have more severe dental disease than their large relatives.


Using these factors, even experienced veterinarians can only approximate a dog’s age – perhaps to within 2 years. Of course, if you’ve always had your dog there’s no problem. However, bringing a rescue dog into the home is very common these days and the task is certainly more difficult, especially if there isn’t a lot of recorded history about them.

We love comments so be sure to leave yours below. Do you know anyone who’s an expert in dog aging? How do they do it? Let us know!

10 comments on “How can you tell how old a dog is? You can estimate

  1. Florence Ki

    I’ve a puppy at home too. But he started to stay with us 1 week after he was born. However, I didn’t know that puppy’s teeth will fall like human. Guess maybe he swallow his tooth? Will that cause an issue as he grows up? Now he is already 3 years old, can I ask is there anything I need to take extra caution about his health? 

    1. Christopher Mitchell Post author

      Hi Florence:

      Puppies often swallow their baby teeth while eating.

      As far as his dental health is concerned, make sure you are regular with his teeth cleaning. See my post on how to clean a dog’s teeth.

      Thank you!

  2. A Habil

    hi, thanks a lot for your very comprehensive guide.

    I never learn about this thing before. My brother once had rescue a dog and had the difficulty to estimate the age. We went to several vet, all of them gave us different estimation. My question is about the activity pevel, do you have a kore objective and measureable figures? If you have it, then I believe, we can be more objective and accurate in terms of the assessment is concern.


    1. Christopher Mitchell Post author

      Hi A Habil:

      It’s nice to know that your brother had a rescue dog!

      I’ve never been able to locate any measurable figures about activity level. I think only veterinarians with a great deal of experience can give a fairly accurate figure.

      Thank you!

  3. Holly Knudson

    I have four dogs and tend other people’s pets so this was an informative article for me. I have noticed arthritis, weight gain, cloudy eyes and tooth decay with my 15-year old Pomeranian. He can’t jump up on the bed or couch anymore, nor can he get through the doggy door. I have to open the entire door for him now. 

    Plus, he’s gotten meaner with age. I know some dogs become more placid. I wish that were the case with him. 

    I was surprised to hear that graying around the muzzle can happen as early as five years of age. I’ve always had little dogs, and you’re right, they are notorious for having horrible teeth as they age. I learned a lot. Thank you!

    1. Christopher Mitchell Post author

      Hi Holly:

      Nice to hear from you. I think you may have responded to another of my posts. 

      Your little Pomeranian sounds like a handful!

      Yes, I’ve seen graying of the muzzle in fairly young dogs – especially the larger breeds.

      It sounds like you really love dogs – that’s so nice to know!

  4. Sujandar Mahesan

    Wow this is amazing. I never thought I can estimate a dogs age by looking at these stuff. Looking at the fur coloring sounds really easy. I’m actually going to give this a try. My neighbor has a pet and I’m going to try guessing it’s age. This is going to be fun. Thank you so much for this article.

    1. Christopher Mitchell Post author

      Hi Sujandar:

      Thanks for your comments!

      Yes, give it a try. However, keep in mind that at best, you can only estimate. Good luck!

  5. Jasmine

    Hey Christopher,

    This was very informative. I don’t have a dog myself, so these techniques of figuring out the dog’s age are all new to me. I think the easiest way to figure out for me would be to go by the dog’s teeth. However, with dogs that have oral cleanings, doesn’t that affect how accurately someone could use the teeth to determine the age?

    1. Christopher Mitchell Post author

      Hi Jasmine:

      Thanks for your comments!

      Yes, most people agree that the teeth are the best indicator of age. However, as you say, if a person is paying attention to their dogs oral health with regular teeth cleaning, it can skew the results. So, it really does come down to estimating using all the factors.


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