Loose stool, not eating, vomitting water
About 3 weeks ago, my husband and I got our first GSD. We went home for a week so we boarded her with a trainer. The trainer said she ate almost all of the 24 pound bag we left with him for the two weeks he has had her training. She is currently on Blue Buffalo Wilderness Puppy food.
Maggie had an appt Saturday with the vet so my husband picked her up Friday from the trainer. In the last 24 hours we have had her back with us, she has not been herself. She is sleeping a lot more, not eating, and has lost a couple of pounds. She is currently 42 lbs at 7 months. You can see her ribs quite easily. She has had tarry, black looking loose stools and is popping frequently, at least every 3 hours. Just under an hour ago, she threw up clear fluid for the first time.
When at the vet on Saturday (8/10/13), they did a fecal test on the stool sample brought in and had no signs of parasites. She received her last set of shots today and had a heartworm test about a month ago that was also negative and has been on Heartworm plus since then. The vet thought it might just be stress and have us some GI pills to help Maggie.
We can't get Maggie to eat anything; rice, soft food, peanut butter, nothing. She is drinking water. My husband and I are really worried about Maggie so any insight would be greatly appreciated. The vomitting happened after we had already taken her to the vet.