Neighbors have selected a dominance theory dog trainer.

As title states, my neighbors have selected a trainer that believes in some sort of dominance training. I overheard Trainer telling Neighbors to jerk their dog around by the collar back and forth until he (Max) stops barking (trying to train manners when people come over). It sounds AWFUL. I was in tears over listening to this dog scream and cry.

Neighbor isn't bad on purpose. They had a new baby and were thinking about relinquishing the dog to a shelter because he was so hard to deal with, but they have instead opted for training! I think it's great. Until they picked this guy.

Most of my information is through my other neighbor as I do not have direct communication with the owners of Max. I left a note introducing myself and offering to help them with positive reinforcement training while never telling them they are bad people. I actually commended them on trying to work things out with their pup. They have not called and I heard them using that training method again. I tried to call the SPCA but it was to late in the evening. I'm not sure what to do. I cant just stand by and listen to this poor dog be brutalized but I don't know what the next move should be? Thank you for any help!