My dog is not well, help!

[has2beshasta]

Hi, my dog is five years old. He seems to be non energetic, won't eat and just lays around, not even lifting his head. This is normally a dog that jumps, runs, and plays all the time. His nose is cold. Had the vet come out yesterday, she gave him antibiotics and pain pills, still no change. Any Ideas?

[Loki Love]

What are the antibiotics for? When did the vet say you should notice a change?