Tail Chaser

Over the last couple of weeks, every once and a while Rowdy will all of the sudden jump up and chase his tail.  It's sort of like a flea has sunk his teeth into it, stinging him into action.  Usually, he will make four or five rounds before he stops or catches his tail.  I have counted up to 20 revolutions of him spinning around and it surprises me that he isn't dizzy when he stops.   Sometimes I think the dog is nuts!