How Can You Tell How Old a Dog Is?

They’re always going to be your baby, of course.

June 26, 2025

Angela Hampton Picture Library / Alamy Stock Photo

In This Article:

How Can I Tell How Old My Rescue Dog Is? How To Tell Age of Dog by Teeth Dog Behavior and Physical Characteristics

If your dog came into your life as an adult, it may be difficult to know exactly how old they are, but you can use certain physical features to estimate their age. Puppies tend to follow a predictable developmental path, so very it can be easier to tell their age (especially if you’re keeping track of their milestones).

Most dogs are considered adults once they are around 12 to 24 months old, depending on their size and breed. After that point, the clues about their age will be more subtle, because they are no longer growing or reaching clear developmental stages. You can make educated guesses on the age of adult dogs by looking for signs of aging, which may include changes to their teeth, eyes, muscle tone, or mobility. Read on to learn some of the specific clues to look out for.

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Main takeaways

You can estimate the age of an adult dog but can never be exactly sure of their age.
It is easier to accurately estimate the age of a puppy due to predictable developmental stages that they experience.
When estimating an adult dog’s age range, look for subtle changes that may occur with age.

Dr. Amy Fox, DVM

Amy Fox, DVM is a small animal veterinarian in New York City. A lifelong animal lover, Dr. Fox studied biology in college and then worked as a veterinary nurse before pursuing veterinary school at Cornell University. She has worked in many different settings including shelter medicine, emergency medicine, general practice, and animal cruelty and forensics. She is especially interested in nutrition, preventative medicine and care for senior pets. Dr. Fox also enjoys writing about veterinary medicine and teaching. In her free time she loves to cook, garden, and go for long runs.