kind of sounds like parvo. my dog had it and had to stay at the vet for a week. had to throw out all her toys and wash everything thoroughly. if thats what it is, good luck. sounds like you may have caught it in time.
The symptoms sound a lot like canine pancreatitis...we had one dog go through that last year...$1500. at the Emergency Vet Hospital...(pricks charged $32. for one Pepcid...then only give him 1/4 of it...but every time he got a dose, they charged us for another full tablet...)
BUT, this is much more common in dogs that have eaten fatty foods, not dog food...(unless it's horribly cheap stuff with a very high fat content, and even then...)