We took Lana to the vet today, and she had not improved. None of the methods that the vet offered seemed like they would be anything more than prolonging the inevitable, so we put her down. She was in rough shape, and it was just not worth it to her to try all these experiments and still end up back where we started. She will be missed. She was a great cat, and I really wish she could have had something that could have been cured.