About a year ago I had my Boston terrier at a dog park and he was playing with an about six month old pit bull. My dog is very submissive and soon the pit had my dog on the ground with no fight with his mouth on my dog’s neck. I immediately scared the dog off and took my dog away. About 8 months later my parents adopted a neutered adult male pit mix from the shelter. They said he was sweet and took him to the dog park. The pit did the same mouth on the neck to a lab and freaked out an owner. I’m since convinced pits need significant training to stop their natural animal directed aggressiveness and don’t feel comfortable letting my dog around one.