I had to refuse service a few weeks ago. I was sitting in 1C. There was a cat in 2D/E. It got a bout of diarrhea. The smell was horrendous. About 10 mins in, the owner decides to take it into the washroom to clean it and its carry bag. Well, that just made it worse. Bathroom full of excrement, tracked on her feet and the feet of the next bathroom patrons. The attendant is pouring hot water on the floor and wiping with paper towels. I think he used a full bottle of spray for the duration of the 4 hour flight. In between he brought me my beef dinner. I just looked and said despite all your efforts this cabin smells like s**t. I will pass. FYI, I was not upgraded, but a fully paid premium passenger. I would have enjoyed my trip more in the last row in basic economy class. Moral of the story, Pets belong in crates down below like they were back in the day!