Cocker Spaniels

I had my 14 wk old pup to the vet today for her shots and found out she had a yeast infection in one ear already!

I know cockers are prone to this , but at 14 weeks!? We have had 4 cockers this one being number 4 and all of them have had ear infections but none this young!

I hope that doesnt mean we are in for a long road of ear ailments. My husband said "Time to put her on ebay!" I told him if she goes I go he was teasing me or kidding, actually, he loves her as much as I do.... but yikes!
and I am soooooo careful to not get water in her ears... The vet meantioned humidity some times causes it and a week ago we had 9 days of humid humid humid. even though we have central air she was out side ..... some of the time does this mean i need to keep her in when it is humid out?