is sheldom the cause of nausea and diarrhea. A stressed out dog will usually cut loose with a puppy wee wee, or even make a non-returnable deposit in the form of a puppy boo boo, but not a diarrhetic one.

The panting could be a sign of a temperature, or pain. If all the dog was doing was panting then you could blaim it on fire crackers. The symptoms you give are those of a sick dog. There are a myriad of causes. You need to get to a Vet for a diagnosis.