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My dog is aging. When is a large or mixed breed dog considered senior?

Updated On September 23rd, 2025

Pet's info: Dog | Mixed Breed | Male | neutered | 7 years and 7 months old

When are my 2 dogs Seniors = Jake - 7 yrs. old, (Shep/Hound (Not Beagle) / Father = unknown). 57 lbs., looks like a 2 foot tall,( to his Back), Shepherd. Skinny. Quite Active, in Summer, Spring, and Fall. Tasha = 4 yrs. old = 96 lbs. (Short-haired Collie/St.Bernard/ Plus = (?). 2-1/2 ft. (to her Back). Looks like a Short-haired Collie. Inactive. Both had "Puppy Mill" Parents. (Rescued). I understand bigger dogs die younger.

1 Answer

Most Helpful Answer

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Answered By Lauren Kennedy, DVM

Veterinarian

Published on February 21st, 2018

Larger dogs do age more quickly than smaller dogs. In the case if your dogs I would say your seven-year-old is ‘middle-aged’ and would consider him a senior dog at about 9 or 10 years of age. The larger dog, Tasha I would say would be middle-aged at about 6 years old. And would consider her a senior dog at age 7 or 8. However, keep in mind, regular veterinary check up and routine preventative healthcare your dogs will have their best chance to live long and happy lives.

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