When you adopt a rescue dog , you probably won’t know the dog’s exact age. Many dogs that end up at shelters and rescues come from unknown pasts, so there’s rarely documentation of when they were born. However, the organizations have to list something on the dog’s bio, so where are those numbers coming from? Keep reading to find out how to tell a dog’s age at a rescue or shelter. Mutts About Pets is reader-supported. When you shop through links on this page, we may earn an af