In the Summer of 2008, I got my rat Skittles, who developed a twist in her neck, and Fa-Ling caught it not long after. Both rats where brought to the vet for treatment, while the medicine cured Skittles tilt neck, it did not resolve Fa-Ling's, but it did kill the cause, so she was no longer contagious. For a short time we thought Fa-Ling wasn't going to make it, and was so close to bringing her to the vet to be put down, but Fa-Ling perked right up, so we knew it wasn't her time yet, she spent about a month or 2 in quarantine to be safe, and then went back with her ratty family. Her head was tilted, but it did not seem to bother her.
Like her sister, Fa-Ling died unexpectedly, she left on Novemeber 29th, over the past month she was losing weight, so she as showing her age. Later that night I went to feed the rats, and I saw Fa-Ling laying stiff in her basket, she looked comfie, so I assume that she died in her sleep, which is a good thing. I hope that is how I go.