The results have come back from the tests they carried out on the stones and have been confirmed as Struvite stones that will most likely have been caused by an infection. These stones are the most common and more easily managed than other types.
She had to have a sterile urine sample taken at the vet on Friday by having a needle inserted into her bladder - ouch! We should get the results back next week, but the local tests they carried out at the vet showed a raised pH level which indicates that there is still an infection present. They have given us an extended course of antibiotics, so hopefully they will work their magic over the next week. She'll need to continue having her strict prescription diet until the infection has gone as this will prevent any new stones forming, but once she is better we should be able to return her to her normal diet.
We're so obsessed that we've now bought our own urine test strips so that we can monitor the pH level at home - the things we do as dog owners!
Here are a couple of pictures that show how well her wound has healed: