This is too weird. Melissa had me groom Lady today. Lady is a german shorthair--mostly white. And on one of her back feet she had a yellow stain. It covered about half of her foot. I tried everything to get it off.....I really scrubbed it........even tried whitening shampoo and grease magic shampoo. Neither of us have a clue where it came from. Any ideas on how to get it off?