My dog Jagger did the same thing a few weeks ago he would cry by the door every 5 minutes go out a nd stand there, vimper while laying down, and he would only rest for seconds. he would come stare at us like he lost his best friend, and was just not himself. we decided to wait it out and in a day and a half he was back to his normal self, being a dork. im sure dogs get all the anoying things we do, indigestion, probably head aches as well, anything. just a whole lot more nerve wracking when they cant tell us whats wrong