New Neighbours

We have lived in our house for 5 years now, and for that entire time, Maggie and Bosley have been the only dogs on our street (well, except for the cute little pug that lives further down the street, but we rarely see him and never hear him).  We have no back lane so our yard backs directly onto our neighbour's yard in the back, which means when we go out on our deck, we have full view of the  neighbours on either side of us and the 3 neighbours directly behind us. Everyday Bosley goes out on the deck and survey's "his" territory and will loudly announce when anything is out of place (such as kids playing on the trampoline in the yard behind us, or the neighbour's cat peeking out the window next door.  Now imagine Bosley's surprise when he went outside Saturday to see a giant Cane Corso in the yard next door.  He howled like I have never heard him howl before!  He ran down the stairs to check out "the invader" but we have a solid fence, so once he goes down the stairs into the yard, he can no longer see into the neighbour's yard.  I called him back in right away and the new neighbours did the same with their dog.  Bosley was not happy.  He has not seen the new dog since (the Masiff seems to be kept inside most of the time, as our dogs are) but when Bosley goes out, he runs to sniff along the fence just to see if he is there.  I sure hope Bosley gets used to his new neighbour soon.