Here in the U.S. it's a violation of several laws, both State and Federal to breed or own a true wolf. There are breeders that cross wolf-dog exisiting breeds with other dogs or even other wolf/dog hybrids.
A neighr, here in thewestern U.S. bought such a pup that would have been about 1/2 wolf (It's hard to tell, so state the breeders) a few years ago and it was a unmitigated disaster. We live in ranching country where both sheep and cattle occupy large areas of unfenced land... I mean like several thousands of acres and several hundreds of livestock.
The 6 month old pup (male) was extremely stand-offish... not only with visitors to the place but also the family that owned him, including other dogs. He always stayed to himself, and the last time I saw him, he wouldn't even acknowldege our presence, much less come and have his ears rubbed.
Anyway, a neighbor some 5 miles away telephoned the owner one morning and told the neighbor he had to come and collect the dead dog and bring his checkbook to pay for the 10 head of sheep the wolf/dog had killed the night before. Seems the wolf cross got out of his kennel and made his way straight to the sheep rancher. The rancher said he was driving by the pasture and saw dust being kicked up and upon investigation (through the telescope on his ever present hunting rifle) saw the dog chasing the sheep and taking them down one by one by the throat and then moving on to the next one. Needless to say he shot the animal from about 150 yards.
Later, after reading and visiting with peiple that had experience with such hybrids siad this wasn't unusual behavior at all and the general consensus is that most such dogs can't really be tamed to the standards expected of the usual dog/pet.
This, from a reputable source is telling:
"...When a wolf reaches sexual maturity (anywhere from 1 to 4 years of age), their role in the pack often changes from that of a pup to an adult expected to contribute to the pack. Status becomes much more important, and the animal may begin testing its packmates to achieve a higher-ranking position in the pack. Testing or challenging of packmates can be transferred onto a human “leader” when a wolf is kept in captivity, causing the animal to be perceived as stubborn, bold or even aggressive.
Domestic dogs tend to mature much earlier (6 to 8 months of age) and have significantly fewer hormonal changes, but the challenging behavior still exists, although it is typically less intense in most breeds compared to wolves. Hybrids can exhibit any combination of wolf or dog maturation rates and behavioral changes.
Additionally, the territorial instinct of wolves to protect their food source by establishing a home range through defecation and urination may be transferred to the owner’s home. A couch or corner of the room may take the place of a tree or rock. Dogs, on the other hand, through domestication, have lost that instinct to urinate or defecate anywhere they feel is their territory and are easily trained to eliminate in a designated area.
Hybrids, being a mix of these two distinct behavior patterns, may have any degree of territorial or testing behavior-from one end of the spectrum to the other...."
The source (International Wolf Center -
http://www.wolf.org/learn/basic-wolf-info/wolves-and-humans/wolf-dog-hybrids/ ) goes on to state, as you'll see, that the efficacy of vacines developed for dogs is not well known for the hybrids...