Hmmm, a vet trip is in order, the "leg falling asleep" - what do you mean? Does she just have trouble standing on it? Is that why you think it has fallen asleep? It could be any number of things, some dogs tend toward hip dysplasia, or luxating patella - hard to know from your description. But between now and when you call the vet, try to keep a list of which side it happens on, and when, that may help them.

The "always hungry" - some dogs are just like that. I knew a perfectly healthy dog who would eat anything he could, even, for example, paper towel if it had touched food, it's just like he didn't have an "off" switch. The wet poop, though, is concerning, and the horrendous gas. What kind of food does she eat - you know, the stuff you feed her intentionally! Some food allergies can present themselves that way. After the vet visit - bring a stool sample (oh, how did people manage before the invention of plastic bags?) and if it's nothing like a parasite, you can try changing her food to something with very few ingredients, like a lamb and rice one, and see if that makes a difference.