So my neighbor's lovely dog Charlie (they could care less about him so he's stuck outside much of the time and I treat him like he's my dog) has major issues with other dogs.
I thought he had been getting better until on Tuesday I found him standing over a different neighbor's dog (black lab, twice his size) snarling, drooling and basically looking like he was about to kill the other dog. The other dog would try to move and Charlie immediately lunged for her neck, barking. I'm pretty sure he was not playing cuz his hackles were all the way up, there was no play bowing and his preferred playing method is being chased.
The other dog's owner's children were standing all around, screaming, probably not helping Charlie's arousal any either.
I finally separated them by calling Charlie's name and throwing a ball for him which he immediately took off after.
I'm pretty sure most of it is that he is trying to get the other dog before it gets him. He's fine if he and the other dog are chasing the same toy or doing something that isn't focused on him, like when dog's sniff each other. He even lets the other dog take his toy from him if they try and then he just calmly watches them play with it. Most of the time. If the dog is much bigger than him or black or both and especially if the dog isn't fixed, he goes bonkers usually. He's snarled at smaller dogs before but he's usually pretty good about it.
Another issue we have is that when he's "stalking" the other dog, or if he's sniffing another dog, or about to go after another dog and I say something to him he immediately ups the aggression. He's very well trained, probably not "excellently" but he is definitely the most obedient, well trained dog in the neighborhood, he has a great recall when other dogs aren't involved and I have no way of practicing with another dog and him.
His owners used to have another dog and they were great together, he had no issues with her. She died about 2 years ago...
I guess what I'm hoping for are maybe some tips as to how to deal with this because I really don't want him to end up killing another dog or something and being put down becuase his owners don't care and wish he was gone (my family can't take him becuase my mom is allergic to dogs and I'm about to go off to college and I can't have pets). I've been working on being totally calm around other dogs and being focused on Charlie so he doesn't get all jealous... but other than that I'm kinda at a loss.
Anyway, sorry for the novel.