When I had my two Basenji girls, and my Border Collie, I often fed them all at the same time in summer when they were out enjoying the dog run, but I stuck around until they were done (not long!!) because the younger one would try to "help" the older one finish her dinner, and both would be happy to enjoy anything the Border Collie left, but not if I was present to glare at them! ;) (the Border Collie would even defer to the cat if she decided to help herself to his meal.)