What is the cause of brown discharge in a cat’s ear?

Brown discharge in the cat’s ears is likely to be caused by ear mites and it is recommended to take it to the cat hospital for examination and treatment. It is important to deworm your cat regularly, not just when you find worms. If there are other pets in the house, isolate and treat the cat as ear mites are contagious. In addition, cat products should be washed and disinfected, and the home environment should be disinfected.