You adopt an adult dog from the local shelter or a stray steals your heart. Either way, you have a new family member but how old is she? Determining the age of an adult dog is not an exact science, even among veterinarians. But there are some physical clues that will help you determine your new dog's age. The teeth. As with people, puppies lose their baby teeth and develop adult teeth at a predetermined point in life. By the time the puppy is 6 months of age, all the baby teeth have been replaced with adult teeth. After this, the accumulation of tartar and wear of the teeth help narrow down the age range.
By 2 years of age, the molars typically have some mild tartar. By 5 years, the tartar is more pronounced and affects the canines as well. This method is not very reliable since the type of diet and whether or not the teeth are brushed can affect tartar buildup. By middle to older age, the incisors are beginning to be worn down.
The eyes. Another method is the presence of lenticular sclerosis. As dogs age, the lens of the eye begins to develop signs of aging. Thin lines can begin to show up on the lens of the eye at around age 6. The lines do not affect vision and are not the same as cataracts, though they can be confused with cataracts.
Gray hair. Graying of the hair on the face varies from dog to dog. As with people, premature graying can occur. For this reason, this is not a reliable method of aging your dog.
Aging an adult dog is difficult and the best you can ask for is an approximation, which may be off by 2 to 4 years. Thankfully, the age of your dog does not affect her ability to provide you with a loving companion, protector and friend.