You can estimate a puppy's age primarily by examining its teeth, as they follow a fairly consistent eruption and replacement schedule:
- Baby (deciduous) teeth begin to erupt around 3 to 4 weeks of age, starting with incisors, followed by canines and premolars by 4 to 6 weeks
- A puppy with fewer than 28 baby teeth and no adult teeth is likely under 8 weeks old
- Permanent adult teeth start to come in around 3 months, with incisors fully replaced by about 5 months and adult canines and premolars erupting between 4 to 6 months. All adult molars appear by 4 to 7 months
- By about 6 months, puppies usually have all their adult teeth, making further age estimation by teeth more difficult
Other physical signs can help:
- Coat color changes such as graying around the muzzle often start around 6-7 years but are less reliable for puppies
- Body condition and behavior also change with age but are less precise than dental examination
For the most accurate age estimate, especially in puppies, a veterinarian can examine the teeth and developmental stages. DNA methylation tests are an emerging scientific method for precise age estimation but are not yet commonly used outside research or specialized settings
. In summary, to tell how old a puppy is, check the number and type of teeth present and their stage of eruption or replacement. This method is reliable up to about 6 months of age, after which it becomes harder to pinpoint age by teeth alone
