More fluid under the skin, Vitamin B injection, a little bit of calcium and a shot of a different kind of antibiotic.
Back home, and she actually seemed like eating almost normally in the evening after some antibiotic, but that apparently wasn't enough, so we brough her back on Wednesday too.
This time it was first X-rays regularly, as by now the concensus was that most likely she was the victim of a foreign body.
They didn't show anything, so on to contrast X-rays, which confirmed that about half the contrast fluid remainded in the stomach, with the rest going through the intestines, so something definitely was wrong in the stomach.
One image showed something which might have been a foreign body, or perhaps a tumour or something, so she was put through exploratory surgery. Nothing was actually found (which was both good and bad), but the contrast fluid was forced out through the stomach, in the hope that it would bring with it whatever it was blocking the exit.
It seems to have worked, as that evenening Roxane started eating almost normally of the regular cat food. I also had glucose solution I fed her with a couple of times per day, as she was rather dehydrated too.
I didn't make her eat the restorative cat food from tins I had gotten at the vet, until Thursday evening when I thought of using the syringe I had been feeding her the antibiotic (which tastes well) and fill it with a mixture of the cat food and water.
That worked rather well, but she wasn't alright by Friday, so back we went to the vet. More Vitamin B, calcium and fluid under the skin, + two shots of a different kind of antibiotic in both thighs. By now she was down to 0.67 kg, but seemed alert enough at the vet.
The Vitamin B and calcium seems to have worked, during the weekend she's been eating rather well of the cat food/water mixture, sometimes so much I thought she'd burst. 20 ml in that small body, and then wanting more!
By yesterday she was up to barely above 0.70 kg and in the evening she took out an insole from one of my boots, so I guess she's got energy for entertainment now, which is a good sign.