Does that come out with a good bath? Or is it a permanent stain?

If permanent I wouldn't retouch it, that's the dog. If a bath fixes it don't shoot until you are brought a clean dog.

That said, you could try:

1. Do your technique and then Art History brush back in the color in the eyes and nose.

2. Go into Lab mode and play with the Lightness channel.

3. Try the Image/Adjustment/Replace Color dialog.