This kind of generalization is not always true because many factors influence the aging of our dogs, such as healthy lifestyle, care, and type of dog.
From a puppy to a senior dog
Puppies mature much faster than human babies. When a dog is one year old, it is as mature as a 15 years old human teenager. The second year of his life is already a little bit slower, and it equals approximately 10 human years. From then on your dog gets older for 4-5 human years every year - depending on the size, breed and some other factors.
Different dogs don’t age equally fast. The most important factors are breed, size, and weight. Small dogs age slowly and therefore have the longest lifespans while bigger breeds age faster. You can bake a cake for 60 human years for a Chihuahua for its 11th birthday, for a Beagle for its 10th birthday and for a German shepherd for its 9th birthday. When a Chihuahua is 16 years old it equals 80 human years while a 16 years old German shepherd can be as old as 120 human years.
Calculate your dog’s age in human years