An assumption here is that a wild wolf will unfailingly rip a dog to shreds at every opportunity.
Sorta odd, dogs are their close cousins and between their ears they can be as different as night and day, anyone who has owned multiple dogs will aver that all had their own personality.
Close studies of wolf packs show the same thing.
Granted, the number one cause of death of healthy adult wolves is probably other wolves, pack members usually attacking intruders on sight. This including close relatives such as dogs and coyotes.
Key word here is "usually". Lone wolves leave their home pack and some may join other packs, a thing impossible is pack killed ALL intruders all the time.
Likewise, in Yellowstone, I recall reading of a remarkable 8 year-old alpha female that was kicked out of her home pack by a coalition of subordinates, who then went on to found another pack, a thing inmpossible if wolves killed strangers ALL the time.
Anyhoo... here's a piece on wolf dispersal...
http://biology.kenyon.edu/stures/compsbergdahl/dispersal.html Dispersal in a wolf pack is a defining trait and a critical tendency of pack dynamics. The dispersal of individual wolves allows for diversity in packs and the formation of new packs. Wolves disperse from their natal pack between 9 and 36 months of age (Mech et al., 1998).
The dispersing wolf is often called a floater. This lone wolf may travel great distances looking for a new pack to join, or perhaps a lone wolf of the opposite sex to mate with and establish a new pack.
Studies have shown that floaters occupy home ranges larger than those of resident wolves, and their range overlaps broadly with several pack ranges (Siller-Zubiri, 1994). In one instance, a female wolf left a study area in Minnesota and was shot by a farmer in Saskatchewan, five hundred miles away (Steinhart, 1995).
I'm still going with actual lone wolf needing company, initially attracted by the dogs. It didn't KILL thedog because it wsn't in that frame of mind is all.
Just my $0.02, Birdwatcher
"...if the gentlemen of Virginia shall send us a dozen of their sons, we would take great care in their education, instruct them in all we know, and make men of them." Canasatego 1744
