Wow.... sad all around. Obviously 23 times seem a bit major but I agree... if there was a dog attacking my dog out on the street .... I would pretty much do anything to protect my dog. He's the most important. And I would do whatever it took.
Take one second to imagine your dog in the head of a MUCH larger animal, probably shrieking, being violentally attacked, you see blood, you are thinking your dog is going to die and he's dying a very painful death... you can't tell me you wouldn't go to extreme measures, and when you do think of something (getting a knife), you are going to sit there and be thinking about "oh I'm probably stabbing this dog too many times...". NO, you just want your dog to be okay. And it sounds like the guy acted quick enough because his dog IS still alive.
Not to mention, it sounds like this dog had a history of acting like this and free roaming. He said it had gone after a kid before too.
Sad all around.
Brit & Jackson