Re: ailing 35 yr old dogwood tree
A lot of trees around here were damaged by the severe drought last year. Due to the lack of rain fall some trees will do what is called a natural pruning. This may be the case with a dog wood. I would suggest you have it checked by an arborist. If you don't have an arborist check with your local extension office, they have a wealth of information available. You might want to take some of the leaves with the black spots on them to the extension office.
Be sure you live your life, because you are a long time dead.-Scottish Proverb