Most cats have normal healthy ears with minimal to no discharge. There may be a very small amount of wax but there should be no smell or excessive discharge. However, some cats can suffer from ear infections caused by bacteria, yeasts or "ear mites".
Common signs of ear infections are excessive discharge, a foul smell and excessive itching. If you notice any discharge, redness or swelling or if you suspect an ear infection, see your veterinarian for evaluation and treatment.