Is my 9-month-old large puppy an adult? Does he need vitamins?
Thank you for using Petco Pet Education Center, formerly Petcoach! A dog is considered an adult at approximately 1 year old, closer to 1.5 years for large breed dogs. Senior is considered a dog over 7-9 years old, also depending on breed. If you believe that Tori weighs too much, I recommend having him evaluated by a vet to see if there are any changes that can be made to his diet. Most puppies/juvenile dogs do not need supplements if they are eating a quality dog food fed in appropriate amounts for their age and breed. If you feel strongly about having Tori take a vitamin, there are many options available in pet stores, but I would recommend that he take a supplement formulated for puppies or juveniles rather than senior or adult dogs. I hope this helps!
Updated on September 23rd, 2025