A dog with an ear yeast infection may show it through some unusual actions like shaking his head repeatedly and excessively scratching his ear. The ears may also have a sour smell, and may contain a discharge that looks a little like slime. This indicates this is probably a yeast infection and not something else. It can be treated at home with some vinegar and water if you can keep the dog still enough to deliver the treatment.
Clean the inside of the ear with a soft cloth or tissue. Gently clean out any pus or wax, which will be brown or black in color.
Mix 1/16 of a cup of warm water with 1/16 of vinegar.
Soak the cotton swabs in the solution. Carefully insert these into the ear. Wipe the inside of the ear and let the solution drip down into the ear canal.
Wipe some of the excess solution off with a tissue, or let the dog shake out the rest.
Repeat the steps two to three times a day for a week until you eliminate the foul smell.