Here's some info from Dr Ian Dunbar on resource guarding:
it applies to dog-human relations and it's harder to find info on what to do about dogs growling at other dogs resource guarding. I was hoping Andrea would post to this thread so I could see what she suggested because I know y'all are going to think i've lost my marbles when i post what i've started doing about dogs in my household growling at other dogs. Jet the trying and Zest! the superstar in training are my growlers. Digital the brindlewonderkid rarely growls at housemates and Pearl-petual motion the malinois has never growled at her housemates.
Okay, so what I am trying to do when Z or J growls at a doggie housemate is to reward the behavior (or ignore, depending on the situation). Yep, see I told you you were going to think i've lost it. I first encountered this sort of thinking from William Campbell's book. (at least i'm 95% sure that's where it came from) he talks about dealing with 2 dogs that dislike each other and doing a "happy dance" when they are within proximity to each other. YEARS later, reading Control Unleashed, there is a totally mind blowing concept called "Getting rid of bad behavoir by rewarding it". What the –-?!?!?! was sort of my reaction, but if you see this through, it really does and can work. She uses this concept with the Look At That game and so I just sort of decided to see where it would take me and sort of took it on faith that she knew what she was talking about. So I did, applied what was outlined and I began to see how this concept works and thought it impressive.
So the behavior I have is J or Z sitting next to me on the sofa and growling as a dog-housemate approaches. "get away, get away, I don't want you near me or my mom!!! GO! GO FAR!!!" What I'm hoping to achieve is "Look, Diggie just got on the sofa, it must mean I get a cookie!" or "I see Diggie over there, I hope he'll come closer so I can get a cookie". I'm trying to change the out look of J or Z from one of resource guarding to one of looking forward to the other dog approaching. I'm trying to change the emotion of a housemate getting on the sofa from a bad thing, to a good thing. I think I am seeing some progress even with Jet who is 13 and has this behavior ingrained for many, many years. Now, I don't think this concept can/should be applied to all or even most behaviors you want extinguished, but it sort of fun to think about.
I do think correcting a dog for this behavior does run the risk of back firing. "oh look, Diggie's approaching the sofa. Last time he approached, mom got mad at me. I should be even MORE proactive and growl at him before he gets withing 5 feet of it this time." Something to think about . . .