A person can tell how old a dog is by looking at the dog's teeth, which means that it is easier to tell a puppy's age than it is to tell an adult dog's age.Â When looking at the puppy or dog's mouth, look at the way that the teeth are forming and how many of them are there.
At 4 weeks, a puppy will have what are called "milk teeth" that will start pushing up through the gums. At 5 months, a puppy will start to get its permanent canine teeth. Between 5 and 7 months, the puppy will get all of the rest of its permanent teeth. Starting at age 1, the dog will get ridges and grooves on the four front incisor teeth. At age 3 or 4, the ridges of the dog's teeth will be rubbed down almost halfway, and by 7 years, the ridges of the dog's teeth will be completely smooth.
For owners, it can be difficult to ascertain how old a puppy or adult dog is based on its teeth, because owners are not always well-versed in dog anatomy. These owners should ask the dog's veterinarian at the next checkup to look at the dog's teeth and give the owner an approximation of the dog's age.