I know your vet said it wasn't ringworm, but I have experienced ringworm when my daughter was given a kitten for valentine's day, and it sure looks like it. I hope & pray for your sake it isn't. If you or your husband or anyone else gets a spot like that its ringworm. We all ended up with a few spots and took forever to get rid of. I would call and question the groomer, see if she my be able to shed some light on it...good luck
