[Crowbob]

Dogwoods are susceptible to Dogwood Twig Borer.

Snip off the dead branch as close to the trunk as possible and look at the cross section to see if there’s a neat, round, tiny little hole in the center. If so, there’s not much you can do about it. Usually, the tree survives but it may have some die-back and lose some bigger branches once in a while. There are some insecticides that will work.