Dogs with large ears frequently suffer from chronic ear infections. Yeast, bacteria, and mites can all cause problems. Most vets sell ear cleaning solutions, which can be used daily. Cleaning the ear with cotton or wipes, apply a cleaning solution, and massaging the solution to reach the whole ear canal is usually done. Ketoconazole is an antifungal that helps to treat yeats infections. Scratching itchy irritated ears can cause the blistering.