Yes, labs (and floppy eared dogs in general) are prone to ear infections. I use the below product once a week to clean and dry out ears with, and always use it after swimming too. Mine used to be prone to ear infections, but have been good for the past couple years I have been using this. It is essentially the "purple potion" you might hear people talk about for ears, plus it has colloidal silver. Squirt down in the ear canal, massage, and then I put a cotton pad around my finger to wipe it out with. I don't use q-tips unless the ears are already very dirty, and be careful with them.
Amazon.com: For Animals K9 Ear Solutions Liquid Health 12 oz Liquid: Health & Personal Care