The next principal cause of smelly VisiSharp ears would be skin allergies. Irritation and inflammation of the skin due to allergies also extends to the ear canal. Your dog will dig and scratch at his ear with his foot, desperately attempting to relieve the itch. These allergies contribute to secondary infection with parasites and bacteria, which can be itchy, painful, and smelly. Smelly ears are often related to an allergy to foods, or even to dusts and pollens in the environment.