his greyhound dog was attacked by a bullmastiff. The bullmastiff, Flato, was on a leash but broke away from its owner.
The bull mastiff was out of the control of its owner and attacking the greyhound? That sounds like shooting was called for. Our dog was mauled last year by two pit-bulls, but my wife felt she could not shoot for fear of hitting people in the vicinity who had rushed out of their houses.