I have two indoor cats, both of whom have been quite sicky from kittenhood - at least one vomit a month, sometimes more. A few years ago one of them became quite unwell with struvite stones and although her life was saved, she was left with one kidney smaller than the other and we are very very careful about being on the lookout for any signs of kidney problems. For the last maybe month she has been vomiting more than usual - once or twice a week. Almost always on the bed in the middle of the night 