William. It’s hard to tell from the photos what specifically is going on with the tree. One possibility is a disease called slime flux also know as bacterial wetwood. As you can tell from the second name this disease is a bacterial disease that is caused when the bacterial gains access to the inside of the tree via openings caused by pruning cuts, storm damage or insect infestations. Once inside the tree the bacteria multiply in the tree's heartwood, producing a foul-smelling, sticky liquid that oozes out of the bark. Oak trees are one of the trees susceptible to slime flux. Once a tree has slime flux it cannot be cured.  See the link for more information.

Symptoms of slime flux include oozing sap, foul order, discolored bark and insect attraction. Slime flux is generally not fatal to a tree but, it can weaken it over time. The constant seepage of sap can create conditions for other pests and diseases to invade.

As I mentioned slime flux is a possiblility but can’t be confirmed from a photo. My recommendation is you contact a certified arborist to come out and to an assessment of the tree. Certified arborists belong to organizations such as the ISA (International Society Arboriculture) and have training in arboricultural and have to pass a test to become certified. The ISA website, Trees Are Good, has a section called find an arborist. Click on that section, enter your location and the site will give you a list of ISA certified arborists in your area.

And one more thing about oak trees. Because of oak wilt disease, oaks should not be pruned between April 15 and October 1st. Oak wilt is a different disease from slime flux. Oak wilt kills oak trees.  For more information see the link.

Slime Flux

Trees Are Good

Oak Wilt