Puppy not eating because of hookworms?

We adopted a puppy a few days ago. The day we adopted him we took him to the vet and had his first shot. He was not eating at all so the next day we took him to a different vet. They did a test and it showed he have hookworms and is anemic. They gave us two meds one for the worms and one to help with iron. The puppy is about 13 weeks old and he wont eat anything. We have tried many different foods but he wont eat. We have to put food in a sirenge and give it to him like we do the meds. We also have to do this with water. Is it ok to do this if this is the only way we can get him to eat? We cant afford a blood transfusion. Should we keep feeding him like we are and keep up with the meds to see if he gets better?