Why Oak Tree disease??
Eye oak tree has weird white cotton ball looking things attached to branches. Husband said they look light toasted marshmallows. Photos show it.
How interesting! This is not something I had seen before so a little research show this is a Wool-Sower Gall.
It should not be an issue, but worth watching.
This link has more information.
It may also be of interest to your County Extension Office.