Roomate came home last night dog got up and greeted him

Apologized for accusing him of hitting him. So i called the vet. Vet said the way he was acting is typical of some dogs when they are ill. SHe said to take his temp. Had to go to the store and get a thermometer, and stick it in his bunghole. Turns out he was running a slight temp, vet said he should shake it a in a couple days. Looks a lil better this mornong but still not himself. The vet said the way he was acting , not coming out of his cage , shaking( common when dogs have a temp) and his tail under his butt, are common with dogs feeling under the weather. Guess ya never know. Thanks guys and happy holidays