I think I know what has happened although I have no proof. Do you know what flock guarding dogs are? they are still used extensively in the more rural parts of europe...go and have a google. Unscrupulous "rescues" are shipping them over here and "rehoming them for a fee" ie selling them they are known by the generic name of Rommie (Roumanian) dogs. They are bred to bond with one or two people and to be fierce with everyone else. They live with the flock to protect it from wolves and thieves. They live in remote areas with little stranger contact. They are working dogs with a massive prey drive. They find it difficult to deal with enclosed spaces, loads of strangers, not being free to make their own decisions, being on a lead.... This is not the first time this has happened, I see comments among my training and rescue friends on FB, this is the first one to get national attention. Its incredibly sad because innocent dogs and humans bear the brunt and the filth who trade in these dogs carry on doing it. They arrive here in vans terrified. Its not unusual that they escape when being unloaded from the van, when being handed over. Its not a question of training, patience, love, firmness, ANYTHING. They are just not suitable for the English environment.