My dog is acting wierd?

My dog just came in from being outside and started to act weird. First off, his head was tilted and he was shaking his head. He then began running around barking, head tilted and crying. We rubbed his ear and he liked it, but when we stopped he continued running barking and shaking his head. Is there any idea what could be wrong with him? We checked his ears but we couldn't see anything....