How to tell a shelter pet’s age

Question:

When a stray dog or cat is picked up and sent to a shelter or rescue, how is its age determined? Is it a “best guess,” or is there some type of blood/genetic test that is performed?

Answer:

Aging animals is a “best guess” — looking at the teeth (baby teeth, adult teeth, missing teeth, “wear” of teeth, and amount of dental disease present) is the first thing we do to determine their age.

We also look at the rest of the body — feet, face, eyes, and skin (pigmentation) — to help build a picture of age.

Another determining factor is if the animal is spayed or neutered. For instance, an unspayed dog will have a small vulvar area, whereas an older female will have a larger vulva, possibly more pigmented. Same with mammary glands: A younger dog (pre-delivering a litter) will have smaller, non-pigmented mammary tissue. While these changes might not be as apparent to non-vets, they’re part of the whole picture.