Why do my dog's ears smell bad?

Normally, a dog's ears should NOT have an odor!  If they do, it indicates a medical problem, such as bacterial infection, yeast infection, ear mite infestation, or even a foreign object such as a seed or twig.   This is a potentially very painful problem for your pet--the lining of the ear canals have as many nerve endings as the cornea of the eye!  Your dog's ears should be examined by one of the Windmill doctors as soon as possible if the ears have an odor.