These are general guidelines as it all depends on what breed your dog is. Most breeds typically tend to live between 10 to 15 years. Larger dog breeds tend to live shorter lives than smaller breeds, typically only reaching the ten year mark.
Puppy – can be up to age 6 months to 18 months.
Adolescence (the age a dog reaches sexual maturity) – starts at 6 to 18 months and lasts to one year or three years.
Adult – starts at 1 year to three years and runs to about age 6 to ten years.
Senior – starts at age 6 to 10 and runs through the entirety of the dog’s remaining years.