According to the American Veterinary Medical Association, most dogs are considered senior by the time they are seven years old. As dogs age, so do their needs and physical limitations. Keeping your pet mobile through appropriate exercise keeps your dog healthier and more mobile. Senior pets often develop illnesses such as arthritis, and it is not uncommon for an older pet to get tired and rest more throughout the day. There are a number of products that your elderly pet can enjoy well into their senior years.