Chasing his Tail

[micdav]

I have an issue with our 4 year old Lab.

The problem: he chases his rear end and runs around in circles.

He can be laying quietly on the leather furniture and all of a sudden will dart down, turn around in circles
several times, go back and smell the area where he was laying.

There's no scooting or whining when this happens.

He's been to two vets, but no answers.

Can anyone give us a hint as to what may be the problem so we can
addresses it.

Thanks.

MIchelle

Your input will be gratefully appreciated.