What kind of dog is she...?
When she eats, does she vomit...or regurgitate her food...?
Have the vets ruled out Megaesophagus....?
What have you done to slow down her eating....?
Try to slow down her eating by putting a couple large rocks in her food bowl...Make sure the rocks are too big for her to swallow...! Put the food around the rocks....the idea is to slow her down, by making her work alittle to get the food. I think you can buy special bowls for dogs that eat too fast.
You can also just try spreading the food on a cookie sheet....this will make her eat slower and smaller bites, instead of just digging in and gulping down..
There is also the possiblility that she has Megaesophagus...
Dogs with megaesophagus need to have their food and water bowls raised, so gravity will help the food get to their stomach. Your vet can check for Megaesophagus.
Connie
Has your vet checked her for something called megaesophagus? The esophagus usually functions as a large muscle that pushes the food from the throat down into the stomach. When megaesophagus is present, the esophagus doesn't move, and this causes the food to sit there where it is sometimes aspirated into the lungs (which would account for the choking) or the food will simply sit in the esophagus where it decays right there. Weight loss and a non-growing baby fit the diagnosis because very little, if any, food ever reaches the stomach, therefore the puppy isn't getting any nutrition.
If this is what is wrong with your puppy you can TRY to teach her how to live with the condition, although it will not be easy. The best way to feed her would be to have her stand on her hind legs so that the esophagus is stretched into a straight line from the throat to the stomach. This way gravity will take the food from her mouth on down into the stomach so that she at least gets some nutrition. Because of the marked dilation of the esophagus the animal has extreme difficulty swallowing as well, so soft, mushy food will probably be the easiest for her to eat because it will slide right down the pipe into the stomach.
I would mention the possibility of a diagnosis of this condition to your vet and get their take on it. I hope for your sake that this isn't it, but from the few symptoms you have given us, this problem is very high up on the list of possibilities. Please keep us up to date on what you find out.
Ghilly