I have a 3 week old puppy that is orphaned. He is very sick, he hasn't pooped in a day and a half won't move around anymore won't eat and isn't responding well. He has been stimulated dozens of times a day as well as rubbing his tummy like a mother would. The vet said he has worms as they are passed along from their mother but he is also anemic vet said to feed and water him with a dropper and continue to stimulate him but gives him a 50/50 chance. He is getting worse and I don't think he will last the night. Please help.

Unfortunately nature is going to take its role. Some of these infant puppies are just not born to make it. Its sad, and I have lost many puppies after 3-4 days of having it in ICU..

Just follow the directions of your vet. He will either pull through or pass away.

Sorry for such grim advise.. but infant puppies are hard to push through crisis such as this.