Thanks Kate and Karlin,
I feel a bit better about what I'm looking at for Ruby's future. My vet is very good and she has cavaliers of her own too.
It's just very worrying that these have all come at once. She is on the food recommended for the stones so fingers crossed we wont have a recurrence.
I will ask the next day in the vets about what type of arthritis too.

Eimear