Everything else aside, isn't it an invasion of privacy to record someone in their own home without proper consent? I know it's outside and all but there's also a fence up if I'm not mistaken, which is an expectation of privacy. Also you can see some of activity going on inside. I'm not saying that I agree with the dog's living situation, but since she's not really in an abusive situation based off of the videos (bar maybe that clip at 8:34-ish) there isn't anything illegal about what they're doing.

You've recorded those owners twice now and both times you haven't been able to really provide any evidence of abuse. Personally I would stop taking videos of them, even if the other neighbors request it. If the neighbors want an inside look to that dog's life, then they can go and ask the owners themselves instead of invading on someone's privacy. Additionally, if someone I didn't know was recording me in an area not generally viewable to the public and I found out, then I would report them right away. It's a huge legal gray area and you could get into a lot of trouble if the owners found out...