Sadly, Seraphim passed away a few days before Christmas. It has been quite busy since then, trying to help Cyrus cope. What we are assuming is that Seraphim had enough energy to try and mask her illness again, yet not fully, so it looked like she was getting better.
On the 19th, we realized that the medications were not really working. She was twitching, and it was so painful to watch my poor little one doing this. That night I stopped giving her the baytril, as it just pained her too much to be constantly taken out of her cage. The next morning, she passed away. My boyfriend burried her next to my first piggie, Gabriel, so at least she will never be alone.
The hardest thing to deal with now is Cyrus, as he knew where she was, and during floor time, he tries to go into that room. He looks for her, and smells her scent on her hairbrush. I intend to try and get a new companion for Cyrus, once I am capable of it, but for now he'll just have to deal with me being his only friend.

Rest in peace little Seraphim, we'll miss you.