Brown discharge in a cat’s ears is usually caused by ear mites. At the same time, the cat will frequently scratch its ears and shake its head. It is necessary to treat the cat in time to avoid worsening of the ear mites. To treat cat ear mites, you must first prepare cotton swabs, ear cleaning solution and ear mite medicine. Use ear cleaning solution and cotton swabs to clean the secretions in the cat's ear canal, and then apply ear mite medicine once a week for a period of time. There will be improvement.