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.
In addition to getting you going, your leg muscles massage your veins and get your blood going! During prolonged periods of sitting or standing, your blood may collect in your legs and ankles. The leg veins stretch easily and may become enlarged by the pressure of the pooled blood. This can cause a dull, aching pain.