Ear discharge in dogs isn't really a specific condition; it's actually a symptom of an underlying issue, like mites or an ear infection.
Because problems like these can be extremely painful, there's no reason to let your dog suffer needlessly. Know the signs and symptoms of dogear problems, how to prevent them, and what you can do when they happen.
Along with ear discharge, if your dog's ears seem painful when they're touched, if your dog is tilting its head to one side, stumbling or circling to one side, pawing or scratching its ears, shaking its head, if the ear or ears seem inflamed, or if there's ear odor, it could be a sign of these common dog ear problems:
Ear mites. Though extremely tiny, ear mites can be a big problem for dogs, especially younger ones. One sign your dog may have mites is a crusty, reddish-brown ear discharge, which often looks like dried shoe polish. Other signs include scratching and head shaking.
There are several treatments for ear mites; some options only kill the adult mites but newer products also eliminate the eggs and the immature forms. Treatment with these products is much easier, so talk to your vet to find the best choice for your dog.
Outer ear infection (otitis externa). A waxy, yellow, or reddish-brown ear discharge can also be a sign your dog has an ear infection, which can be a result of allergies, mites, polyps, overproduction of ear wax, excessive bathing or swimming (which can leave too much moisture in the ears), or other problems. Additional signs your dog might have an ear infection are a bad or fruity odor from the ears; pain; hot or inflamed ears; scratching; or head shaking.
A problem like this requires prompt attention from your veterinarian. Treating an external ear infection may require an antibiotic as well as an antifungal lotion, oral medication, an ear-cleaning solution, or an ear-drying solution. Chronic issues sometimes need surgery.
Inner ear infection (otitis interna) or middle ear infection (otitis media). An untreated external ear infection can easily lead to a very painful middle or inner ear infection, both of which have similar signs to otitis externa, along with reluctance to open the mouth or problems with balance. Some dogs may walk in circles or become nauseous.
Treatment for middle or inner ear infections may require antibiotics, flushing the ear by your vet, or surgery if the infection is serious.