Dogs with floppy ears are notorious for getting ear infections. This is due to poor air circulation around the ear canal, lack of proper, regular cleaning and sometimes allergies. Often diet changes can be beneficial in eliminating the problem of chronic ear infections caused by allergies. There are many things in a dogs diet that might trigger an allergic reaction which will manifest in ear infections or skin problems.
Using gentle, natural ear cleaning products on a regular basis is a good start in preventing ear problems. There are solutions you can make at home and those that you can buy premade that work well. Aloe based cleaners are wonderful for regular maintenance and are non irritating. I really like a homemade solution of half vinegar and half water.
Feeding your dog a limited ingredient, high quality,natural dog food is another step in preventing these chronic ear infections.
If your dog does get an ear infection, there are natural remedies that can be used.
I had a dog that had chronic yeast infection in the ears. I cleaned them every day with gentle store bought ear cleaner and they would be just as bad the next day. I took her to the vet and he put her on antibiotics. They cleared it up temporarily but it came back immediately. Then I read that if your dog had yeast problems, worming it might help. So I wormed her twice over a two week period with pyrantel pamoate. I also started cleaning her ears with the water/vinegar mixture. The yeast infection cleared up, never to return!
This video demonstrates techniques for cleaning ears and treating ear infections.