Can animals be altruistic?

Do we help people simple because we want to help them? or do we help them for egoistic reasons? Psychologists have had the same questions for many years. Some people assume no one can really be altruistic. They assume we help others for reasons such as reliving our own distress, experiencing the joy of others we've helped, or anticipating that people we've helped will be more likely to reciprocate by helping us later. On the other hand, other scientists, such as Daniel Batson, do believe people simple help others due to pure empathy. If people can by altruistic, can animals be too?

According to a recent news, a dog named Duncan, saved his owner from a house fire. The dog did not make it out of the fire and was buried in the flames. Does altrustic apply to both human and animals? If not, how can we explain what Duncan did?

http://abcnews.go.com/US/dog-dies-saving-owner-fire/story?id=14866538#.TuUU_mNCq0s