The size of the dog
Size is another factor to consider when choosing a dog breed for seniors. For example, large dog breeds can be good guardians, but there is always the risk they knock the person down. Also, these dogs have a big appetite and can be a significant expense for older adults. Also, large dog breeds are prone to some medical conditions, including hip dysplasia, so having a big dog can result in higher veterinary bills. If you want a big dog, look for a breed with a docile disposition like a Saint Bernard or a Newfoundland.
Small dog breeds tend to be easier to handle. They also generally require less exercise than most large dog breeds. But keep in mind that small dogs tend to bark more often. However, with good training, you can minimize this behavior.