A little over a week ago, I lost my dear friend Marble from unknown causes. Shortly after playing with her, we found her on her side, not able to get up. She had seizure-like fits and seemed to be arching her back in pain. She passed waste no problem, but had no will to eat. I sat with her until the very end, which was only about an hour after we discovered her state. Today I lost another. Azu was supposed to help us heal after Marble's death. We got her in a local pet store and seemed to be in good shape. She was put in the same cage, with the same cage mate as her predecessor. She was fine, happy, lively even. She had a big appetite like the others and loved fresh grass. Today is directly a week since we first got her, and we found her limp and stiff in her cage just hours ago. I'm worried about the state of my piggies and why this is suddenly happening. Any ideas why...?