For the past couple of days I noticed Tundra shaking head so thought it might be ear mites. Took him to the vet yesterday and it's a yeast infection so he's on Mometamax for 10 days. Also bought an ear cleaning solution she said to use once a week that has drying agents in it. Don't know why or where he "got" this.....he doesn't go swimming but occasionally plays in the sprinkler...or it just happened. He's never had any problems in the past. We did move almost two months ago from northwest WY to central Louisiana so the environment is definitely wetter(but Tundra is a firm believer in A/C)! And I had to switch his food because Canidae is not sold here. I put him on Purina Pro Plan (I bought the Performance by mistake and he definitely doesn't need the extra calories). The one difference I seem to notice in ingredients between the two is that the Purina line has corn and/or wheat which the Canidae didn't. I did mention it to the vet that we had been on a different food for almost two months, but she didn't think that was the cause. He doesn't show any indications of being itchy or licking his feet, etc. Anyone have any thoughts on this?