"pit bulls" used to be referred to as "the nanny dog" ,, shar-pei's are violent dogs bred for fighting and you can bet that these particular dogs were not bred for good temperament... Nothing is meaner than the inbred breeds ,, Chihuahuas ... but they can't inflict the damage a full size breed can... At one time Collies were the most dangerous breed due to indiscriminate breeding they were like giant Chihuahuas...