I believe it is a Saluki/Poodle Mix.
Strange looking dog, IMHO. If he looks directly at me, his expression makes me shiver. But not in a good way. I'm not sure why.

These neighbors' other dog is a Coon Hound/Boxer Mix.
Both large dogs like to come into our yard and lick up stuff on the dirt mounds left behind by our August septic system repairs: https://pbase.com/britestar/image/171902059
I have no idea of why these dogs are attracted to the area since the septic system had no "leaks". Maybe they just like to eat dirt.

Meanwhile, these dogs go "potty" in our yard when they come over.
Needless to say, this doesn't thrill me, but it is what it is. These neighbors' former dog used to routinely poop in front of our mail box where we'd step into the mess when getting our mail.
So these current dogs aren't quite as bad.

I'm sure the neighbors (senior citizens) love the dogs very much.
Just wish they would keep them at home.