Instructions
Check to see if the puppy's eyes are open yet. Puppies are born with their eyes closed. They usually open their eyes about 10 to 12 days after birth.
Examine the puppy's teeth. Dogs are usually born without teeth. The first teeth, called "milk teeth," appear sometime during the third week of a puppy's life. Within two to three weeks, more teeth will emerge until the pup has a set of 28 sharp teeth. This is when the teething period begins. During this stage, the puppy's need to mouth and chew will be evident. By 6 or 7 months, the puppy will have acquired a full set of teeth.
Watch the puppy to see how well it stands and walks. By the age of 4 weeks, a puppy is usually able to run and chase its litter mates and should have good motor control of its limbs.
Observe the puppy's interaction with its litter mates. A puppy that is 3 weeks old is capable of barking, growling and tail-wagging.
How to Find Out a Puppy's Age
Determining the age of a puppy is easier than figuring out the age of an older dog. Puppies go through many physical changes in a very short period of time following birth, so it is relatively simple to estimate the animal's age by looking at a few important features. However, determining a dog's age can sometimes be difficult even for veterinarians, because there are so many factors to take into consideration, such as breed, health and environment.