Yeast Infection in ear causes

One of my cats has a recurring issue with getting yeast infections in his ears. We have been trying to narrow down the issue that is causing it. We originally thought it was an issue with being allergic to his food and switched to a organic brand that does not contain fish or yeast. It's been a year and he has not had any issues with his ears until just recently. This seems odd that he would go so long without the issue eating this brand of food only for it to happen again if the issue lied with the food. I noticed that my other cat likes to really lick the inside of his ears and knowing that cat's have yeast in their saliva I thought that he may be creating a moist environment inside the ear that allows the yeast to thrive. I haven't been able to find any information about this being a possibility so I would like to know if anyone has information or experience in this matter. 

I've heard that if your cat consumes food that contains carbs, eating enough of it can make yeast infections more difficult to treat. Look at the ingredient list on your kitty's food and see if you can find any. These would include grains as well as starchy vegetables like pea and pea protein, sweet potatoes and potatoes, tapioca, and even carrots, for example. Canned foods that have "gravy" tend to be higher in carbs. Look for pate varieties like Merrick's purrfect bistro line (make sure it says pate, they do have other types). If you feed dry, that's a guarantee there's even higher amounts of carbs in them. All kibble will have some form of starch to retain its shape. And look to your cat treats, too. Perhaps there's been an increased intake of starch or the food you've been giving has had reformulation of some kind and you didn't notice?

I don't think you need to go organic, just as long as the food is high protein, moderate fat and very low carb (less than 10% is ideal). Hope you get the yeast under control very soon, good vibes to you and your kitty!

A chicken allergy showed up in my kitty by way of yeast infection in his ears.  I had been feeding chicken almost exclusively because he has IBD and can't tolerate beef.  Feeding one protein exclusively for a long period of time can cause an allergy to that protein.  I think there are also other reasons for ear issues.  Was your kitty a rescue?  I know a long standing ear mite infestation can cause life long ear issues.