If you take a picture, maybe we can help with breed type.
I would wait a few days and if you're still concerned it never hurts to talk to the neighbors.
Just make it seem friendly, like maybe suggest letting you meet their new dog and let your dogs meet each other something like that?
Then they could possibly explain the new dog, why it howls?
Here in my county I've called the animal people before, I just told them I had a casual concern, not pointing fingers and they were more than willing to check it out and got back to me to let me know I had no reason to be concerned.
The animal people would rather check it early than when it's too late.
Just a side note