She gets an aspirin-based fluid medication. Now, if a human takes to many aspirins, he will get severe problems with his stomach (and I'm experienced in that, having taken between 4 and 6 aspirins every day for nearly three years). The same goes for animals. So, it might be that the medication is causing some stomach problems. For this coming week I've had to reduce the amount of medication and hopefully it will get better. If it doesn't get better, she might have to come off the medication completely, which in turn means the cancer doesn't get treated.
She's causing me some grieve this nervous little pussycat!