Large Breed Longevity. The average lifespan of all dogs -- both small and large -- is 12.8 years, reports pets.ca, a Canadian pet information provider. Some larger dogs tend not to live that long, and data varies considerably by breed.
Aching Legs. Aching Legs and Feet. Injury is the most common cause of leg pain (aching legs). However, even a simple back pain can cause your legs to ache depending on the degree of pain. Usually, elders and diabetics and people with poor circulation are the ones who experience leg pain especially at night.
Leg cramps are common. The cause is not known in most cases. However, some medications and diseases sometimes cause leg cramps. Regular calf stretching exercises may prevent leg cramps. Quinine tablets may be advised as a last resort if you have cramps regularly. A leg cramp is a pain that comes from a leg muscle. It is due to a muscle spasm, which is when a muscle contracts too hard. It usually occurs in a calf muscle, below and behind a knee. The small muscles of the feet are sometimes affected.