I guess Riley has been to...
Newark, or Newark-on-Trent, England.
My prefix is unused.
We called an unused thing as "a new thing".
My suffix is a forest removed.
The flood is coming, cut down all the woods to make an ark!
My infix is a reunited analogue.
Unite all the manpower to engage a war.
I am all alone but for a dog.
Well, there is one new built ark, so it is alone.
However, there is a place that held a dog show not far from the downtown area.
