Last weekend there was this tiny stray dog in my backyard.
I took her straight to the vet for a microchip check. No luck.
She was cute and shy, but also extremely dog-aggressive. As in, she wanted to attack the neighbor's German Shepherds through the fence, and also took every opportunity to start a fight with my dogs.
So I closed her up in our bathroom when I wasn't taking her out to potty--and kept her on a leash when she was outside, so she couldn't charge the fence. Separation is possibly the best method of dealing with dog-aggression.
Dozer could have cared less. He ignored the obnoxious little dog and all of her growling threats toward him. As long as he can walk away from another dog, he will.
Star is more complicated. She really likes to tromple all over other dogs. If the other dog is a playful little puppy who's into rough play, it works out great for both dogs. If the other dog is aggressive rather than playful, the interaction can turn sour, and a little dog is obviously at a disadvantage.
I kept Star in a down-stay whenever I had to take the little dog out of the bathroom. Star restrained herself admirably, even though she clearly wished that the stray could be a tromple-buddy. She kept play-bowing to the little dog from her down position across the room, which was a sweet gesture but only sent the little dog to the end of her leash with a ferocious roar.
Anyway, after walking the entire neighborhood asking people if they recognized the dog ("Nope"), posting Found Dog notices on Craigslist and the local animal shelter websites, and making posters, it happened that the dog started barking in our bathroom... and I immediately recognized the bark. Yes, folks, I can hear a dog bark and I can guess which neighbor's dog it is.
There is a neighbor a few houses down with a solid fence, so no one can see the dog she has, but you can hear it barking during the day. This little dog's bark sounded the same.
So I managed to get the dog back to its owner in about 24 hours.
Usually I would suggest a microchip or a collar, but this neighbor doesn't speak English very well, and I don't know enough Spanish to do more than to tell her that her car is yellow, or ask whether her head is made of cabbage. So unfortunately the responsible ownership tips had to be left out. I did manage to say that "tu perro recibe un bano" (still not sure I said what I meant), and she said Gracias.
This was quite possibly the most dog-aggressive dog I have ever had the displeasure of temporarily housing. I think it serves as yet another important reminder that dog-aggression can be a problem with dogs of any shape, size, breed, or mix—and further, that the triggers and consequences of dog-aggression are different with EVERY dog. Every dog is an individual and should be evaluated as an individual.