As a guideline, cats and small to medium breed dogs are considered to be senior pets from the age of 7 years old. Large breed dogs are considered senior from the age of 5 onwards. This age is the best time to start talking to your vet about possible age-related conditions in your pet, whether it is the right time to switch their food to senior pet food, and the best senior food to switch to.
Be on the lookout for common signs of ageing in your pet, like weight changes, a dull coat or mobility problems. Get more information about the signs of aging in dogs here.