Our lovely cat has been vomiting - about 2 days every week for the last 3 weeks (could be more as he goes out). He seems fine in between and is still eating - 2 pouches/ day and small bowl of biscuits. The vomit is dark brown, smells disgusting ( I thought it was diarrhoea initially) and is mainly undigested biscuits and brown liquid. He has lost a bit of weight since Xmas but he was a bit porky so we have reduced his biscuits and he now looks normal weight.
Should I stop his biscuits/ change the brand (always had Iams) /take him to the vets???