Decreased bone mass isn’t as problematic for dogs as for people. Yes, as they age dogs lose bone. But because they have a shorter lifespan, they don’t tend to develop osteoporosis. Their loss of bone mass, in fact, is rarely great enough to cause a problem like a fracture upon falling. If a dog does break a bone, it usually signifies a localized disease of the bone — such as cancer — rather than decreased bone density throughout the body.