From experience Yeast can be very frustrating and difficult to get rid of especially when dealing with White water dogs!. The fur turns red where yeast is an issue and has a foul smell. If you dog is in the water all the time this becomes an issue. My Female Fiona lives in my pool and has red on her chest and a couple other areas due to this issue. It is hard to get rid of. Of course keeping them dry is one way to avoid the issue but try telling that to a dog that loves to swim. I have to bathe her 3x a week with a special Antifungal shampoo and leave it on for 10min for at least at month. If yeast is in the ears then you may need a vet visit to get ear drops to help. Although Fiona doesn't seem to have a problem with itching I know some dogs can be miserable with itching from having Yeast. Common places they also get it is in-between the toes and gentile area.  Any place that has warm moisture is more prone to getting yeast. I have heard other things such as trying gold medal medicated powder or hydrogen peroxide on the area. Researching the issue and talking to your vet about yeast is always a good idea.