Thanks for your reply. Shadow is perky this morning and acting normally. I wonder if he didn't find something with red dye or somesuch in it. The piece of paper I used to mop up the pinkish foam (I saved it in a plastic bag) is almost white now. Thanks for your answer and I will take Shadow to his appointment tomorrow if he continues to improve.
Oops! I hope I didn't authorize payment of another $18. I'm happy to pay the first $18, but have no other questions at this time. Thanks. Leni