My dog's ears itch. What to do

Take to the vet

Also, if they smell like yeast, it might be a yeast infection. That can be treated with some topical medicine from your vet. If they stick, it could be a bacterial infection and same thing, go to the vet for medicine.

if there is brownish waxy stuff inside ears it's possible they have ear mites. If they have allergies, they itch. If they have an infection they do the same so there are many possibilities.