Well there is alot in here, where to start.
All breeds of dogd are capable of biting, usually poor husbandry and care on the owners part. My nephew nearly lost his face to a chinese pug, the dog had never been around children my nephew was only 18months old. My sister thankfully was close enough to grab him when the dog lunged, it was her MIL and FIL dog. Jack Russels are also known for biting, I think it was Natalie Embrougliah (bad spelling) who was laying on the floor curled up with her JR when he turned and took a chunk out of her face for no apparent reason. My husband was bit by a wolf/husky cross for trying to pick up a bag of peanuts of the floor at a friends house because the dog figured everything on the floor belonged to him. My mom drove courier and while delivering a package a chihuaha (sp?) came up and sank its teeth into her heel doing serious tendon damage thankfully missing the akeles (sp?) tendon. Too many stupid people own dogs unfortunately.
Almost any animal has the potential to do harm and yes even kill. My personal favorite animal is a Rotti (also fond of huskies, sheps, Dobi's without the ears and tail done, mastiffs, greyhounds, boxers, great danes, get the picture
) but I don't think it is fair to keep them in the city, I think they deserve a lot of space and I don't have the time to dedicate to obediance classes and taking one out for walks all the time wich they need and DH is anti large dog. My husband wants a chinese pug, no problem as long as he is willing to train it, and take care of it properly as I do my snakes. Husbandry is everything no matter the animal.
Most of my family have farms up north peace country and lots of horse back riding growing up. Yes a horse can do serious damage again all depends on the horse. I was an 1" away from being dead when the horse I was next to was spooked and reared up and jumped forward and bucked, her back hooves came an 1" from my head. She was a 2 yr old and my uncle had just started her training and my other cousin came out and scared her thinking it would be funny.
Stupid people cause bad names for animals.