So Hercules had been doing great until about a day and a half ago, he had been eating well and his stool had been a little soft mostly we thought do to a parasite the vet said was common. He was on medication and has been eating the fromms pink puppy food. He has even gained 2.5 lbs in a little over a week but starting yesterday his stool was pretty much liquid. We took him to the vet this morning and they kind of bashed fromms as a good and then said that he had a Protozoa in his stool and put him on a different medication and a prescription food. This was a few hours ago and after eating his first meal of the new food he vommitted it all up and is now refusing to eat either the fromms of the prescription food.. I'm getting a little concerned. Any ideas?