Hi Stacey,

Thank you for reaching out to the help line. I believe your tree may have a fungal disease. A serious fungal disease of dogwoods, called Dogwood Anthracnose can attack a tree in two ways: 1) by impacting leaves and blossoms, initially causing leaf spots with a sort of purplish edge. 2) by disrupting the tree's vascular system, causing dark colored lesions or indents on branches and twigs. As it develops, twigs and branches will begin to turn yellow or dark brownish black and cause dieback. This stress to the tree can often cause numerous small shoots or saplings to sprout from the trunk.

You will want to prune and discard any affected twigs or branches and rake up any leaves that may have fallen in the area. Large, perennial cankers on scaffold branches may be more difficult to manage, since removal may seriously degrade the aesthetic value and overall health of the tree. Collect and discard all infected leaves that are shed throughout the growing season, as the pathogen overwinters in fallen debris. Limit additional stresses on the tree, such drought or mechanical damage from mowers and trimers. Here are a few links that you may find useful:

Red Twig Dogwood

Dogwood Anthracnose (management)

Please feel free to reach out again if you have further questions. I hope this helps!