Vomiting, diarrhea, loss of appetite, lethargy?

Here is what is going on: My dog, Gunner, (1 year old, 1/2 german shepherd and 1/2 pit bull) has been acting very lethargic and hasn't been eating ANY of his dog food since Saturday(10/23). He ate a few treats and pieces of chicken here and there, but not a whole meal or anything. He also hasn't been drinking much water. He will only go to his water bowl about once a day, so I've been trying to give him ice cubes which works about half the time. He hasn't done much but sleep, although we did give him a tennis ball to play with, and he destroyed it within minutes as he usually does. But he is acting depressed, and lethargic for the most part. Yesterday morning he started vomiting. He threw up about 3 or 4 times total yesterday, and once this morning. He also had diarrhea this morning. There was no blood in the vomit or the diarrhea though. We visited a vet this morning and they said he didn't look that bad to him, he must have gotten into something or it could be worms, but she said she really didn't think he had parvo. What should I do? I can't afford another vet visit. If it's just a stomach ache/virus, how long before it clears out of his system?

[Dr. Carol Osborne, DVM]

Check the pet food and dog treats you are feeding to be sure none of them are on the FDA's pet food recall list.

I would immediately stop feeding all of this, try a home made bland diet and if this hasn't resolved in a day or two, blood tests and x-rays would be helpful as well as fluids for hydration.

If your dog is currently vaccinated, I doubt Parvo is the problem. Worms are easily diagnosed with a fecal exam performed by your vet.