Instructions
Put your Labrador puppy on a table, couch, chair or your lap. This will help keep your puppy confined while you examine it and will make it harder for the puppy to get away. Ask someone to help you hold the puppy if it squirms or tries to escape.
Pry open the puppy's mouth. Put one hand on top of the puppy's snout and one hand on the bottom, and gently pull the jaws open until you can see inside the puppy's mouth.
Examine the Labrador puppy's mouth for any visible teeth. If there are no visible teeth, the puppy is less than 1 month old because dog's baby teeth come in when the puppy is between 4 and 6 weeks old. Baby teeth will look different from permanent teeth because baby teeth are small, sharp and pointy.
Check for permanent central incisors. Central incisors are front teeth and they usually come in when the puppy is between 3 and 5 months old.
Look for incisive extreme teeth, which are next to the two front teeth. Check for the outer incisors, known as corner incisors, next to the incisive extreme teeth. The incisive extreme teeth and outer incisors will come in when the puppy is about 5 months old, according to the Puppy Basics website.
Check for canine teeth. Canine teeth are big, sharp, pointy teeth that resemble fangs and are found next to the incisors. The presence of canine teeth means the Labrador puppy is at least 5 months old. The canine teeth usually finish coming in by the time the puppy is 6 months old.
Examine the Labrador puppy's mouth for any premolars behind the canine teeth. The presence of premolars means the puppy is between 4 and 6 months old.
Check for any molars behind the premolars. According to the Pet Place website, most puppies get their molars between 5 and 7 months old.
How to Determine the Age of a Lab Puppy
Trying to discover the age of a puppy can be as easy as looking in its mouth. Teeth are one of the better ways to determine the age of a puppy because each type of tooth comes in at a certain age, usually starting between 4 to 5 months for Labrador retrievers. Permanent teeth on many dog breeds come in between 6 and 7 months old, but larger breeds like Labrador retrievers tend to get their teeth sooner, according to the Pet Place website.