A dogs ears are constructed in such a manner that it makes them prone to infections. Their ear canal drops down and turns sharply before it meets the eardrum, crating a dark and dank place for infection causing bacteria and yeast to overgrow when exposed to moisture. If you have a floppy eared dog, they are even more susceptible because their ear canals don't get the much needed air flow that helps to dry the moisture that accumulates.
If your dog's prone to infection, after he dunks in the lake or tromps through the snow, then you may want to try a solution of one part acidic apple cider vinegar and one part astringent witch hazel to lower the pH and up the ears' natural infection power. If your dogs canals are inflamed or he's been scratching, swap witch hazel for non-stinging spring water.
Pour the mixture into the ear canal; fill it to the brim, and then compress the canal with your thumb and fingers. Keeping your dog as till as you can, vigorously massage the entire length of the canal from the outside. It'll be O.K. to give it a good squeeze. After a few minutes of kneading, let him shake his head and then clear out any remaining solution with a light towel. Repeat for the other ear.
Chronic infections may be from food allergies or sensitivities.
