I noticed a lump on my cats mouth a week ago, i asumed it was a bee sting so left it (as we were going on holiday the next day), anyway its still there and looks like ulcers (sp) on his lower lip and its a bit puffy. I don't want to have to take him to the vets if its nothing major (as they charge a fortune just to be seen and we had a large vets bill last month as he was very poorly). Could it be a reaction to food? he its a selection of food (what evers on offer in the shops)?