For those wondering about Bij, it's most odd and the vets don't have a clue because its definitely not arthritis and they're not sure if the x-rays show anything significant, however I have noticed something. Since she came back from the vets she has been a little sore (poor darling), but she seems to be mostly dry. Now, while she was at the vets they did one last test, they looked at her anal gland and it was full and the vet emptied it. What I'm wondering is if she has a problem with that and it's not working properly and if it stays full whether it confuses the rest of her system or something. It's supposed to empty every time she goes, but it clearly hasn't been and maybe that's the issue.
The problem is though, she's also been emptied out when the vets took their tests, so it could just be that, that has made her dryer. We have to wait and see. If the gland is the issue we might be able to empty it for her every now and then and keep her working okay.