Is this dogwood tree healthy?

[gsxrken]

I planted a dogwood tree back in May (just north of NYC) and I’m worried that some of the lower leaf clusters seem to be dying. I’ve also included a photo of the seeming healthy upper part of the tree which seems fine, so I wonder if deer are getting to the lower parts, but then why would the leaves even be on the tree? Anyway I don’t know if this symptomatic of a blight or some issue within my control to stop. More water, less water… fertilizer, or some treatment I should apply?
We buried part of my heart under this tree when my little dog Delilah passed. I am emotionally invested in this tribute of a tree and would like to do ensure it thrives.
Thanks for any help.

[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.