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.

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Dr. Amy Fox, DVM

Amy Fox, DVM is a small animal veterinarian in New York City with over thirteen years of experience in a mixture of general practice, emergency medicine, and shelter medicine. A lifelong animal lover, Dr. Fox studied biology in college and then worked as a veterinary nurse before pursuing veterinary school at Cornell University. Her expertise includes surgery, dentistry, and management of chronic conditions, and she is interested in toxicology, pain management, nutrition, care of senior pets, and educational outreach. Dr. Fox also enjoys writing about veterinary medicine and teaching, and her work has previously appeared in Spruce Pets. In her free time, she loves to cook, garden, go for long runs, and hang out with her goofy mixed-breed dog May, who provides never ending comic relief!