my 2 yr old caring terrier just randomy started acting very strange today. Panting, shaky, nervous, ears down, won't leave our sides... wants to be on the couch only, if we leave the couch, he stays but paces and whines... constant need to be petted, pacing turning circles, won't lay, or eat, have to force him to go outside, for which he struggles the whole time to drag us right back in.