What Causes Extreme Bloating? I Have A 3 Week Old Dachshund Whose Mother Has Stopped Feeding Him. He Is Very Lethargic And His Stomach Is Bloated Terribly.

If for some reason that is not possible (and by that I mean not physically possible, no other reason is acceptable).. Than youwill have to do what you can to help him.. But understand that unless you've had a lot of experience with this sort of thing, there's a very good chance he will die without medical help. 

Is he eliminating?  You may still need to stimulate him by rubbing his anus with a warm damp cloth.  If he's not eliminating, he may be constipated... it is rare for a puppy to become constipated, but if one does, this can be corrected by using children's Castoria or by giving an enema. An enema can be given, using a #8 feeding tube, attached to a syringe, filled with approximately 2-5 cc's of warm water (the amount depends on the size of the puppy). Put a dab of Vaseline on the end of the tube and insert it into the rectum, maybe an inch (again, how far in, depends on the size of the puppy). Gently push the plunger until the liquid is entirely gone from the syringe. Within a few minutes, you will get results. Constipation rarely occurs in puppies that are nursing, but it can be a frequent problem in hand-raised litters, especially if the formula isn't thinned out enough. If constipation continues to be a problem with hand-feeding, a teaspoon of Karo syrup can be added to the formula.... In the case of an extreme emergency when a puppy is really bloated and not nursing, it is possible to remove contents from the stomach. If this is attempted, it should be done very carefully, using a feeding tube and syringe.