Why would 1 month old puppy not growing?

Answer 1

i have a 1 month old Gordon setter puppy that is the runt of the litter of 8 pups. he is not growing and weighs only 1 pound 4 ounces. he spits up alot when nursing acts like he is gagging after he eats . our country vet has checked him out and is at a lost at what is wrong with him. she gave us a milk supplement, and a protein paste to try. he will lick both of those out of a bowl or off your hand. he was losing weight but now has been at the same weight for 3 days. he is on a antibiotic now cause he sounds raspy in his lungs. at times he is up playing like a normal pup. his brothers and sisters are 2-3 times his size so we had to separate them cause they played to rough with him. the vet told me to try to give him watered down baby rice cereal to see if that would fatten him up, he ate it then started to gag and choke so i turned him upside down and he threw it up and went limp i thought he died. but we got him moving again. our vet cant believe he is still alive. and another thing i have only seen him poop 1 time and that was just a drop. the vet had me give him 2 drops of karo syrup to get his bowels moving but it hasn't worked. the vet said he would be dead by now if he couldn't poop, but i am with him all the time and he tries to squat to go but never does. any suggestions? the puppy will be 5 weeks old on Feb 5 thank you Yvonne Chapman