Trying to figure out what is going on with the health of one of my live oak trees. Starting to see signs of the same symptoms in adjacent oaks. Anyone have experience for how to treat?

I'm hoping this is not oak wilt. Any advice greatly appreciated.

Last 2 look like old blood splatter.

That doesn't look like oak wilt to me. In the wilt the discoloration is directly along the leaf mid-vein but does radiate out to edge of leaf in distinctive pattern. Hence it is called venial necrosis.

Thanks man. What's the cause?

Tree disease caused by a fungus. The fungus invades and disables the water conducting system. Some species of oak are more affected than others.

I have a very little publication entitled "How to Identify and Manage Oak Wilt in Texas" that was produced by the USDA but senior author David Appel was with Department of Plant Pathology & Microbiology at TAMU. Might find article on-line or by calling local USDA or A&M Department directly. Also check www.texasoakwilt.org.