Aggression towards humans from our rescue greyhound. How normal is this and what can we do?

[Greyhoundboi]

Our greyhound is 4 years old and we've owned him for close to 18months now. He used to be a racer but retired early due to injury. When we got him we were told he was fearful around other non-greyhound dogs and as a result would get aggressive (barking, lunging, snapping), and we knew he likely wouldn't ever be the sort of dog we could take to an off-leash dogpark. We're ok with this and have just always walked him on a leash and with a muzzle in case any other off-leash dogs approach him unexpectedly. He has also always been a bit of a resource guarder and would give us a growl if we approached his bed or toys as well, but we've been fine to give him his space when he's in 'his' areas. 

However over the past 6 months his aggression towards humans seems to have escalated. This has manifested through:

• Barking aggressively at anyone unfamiliar who knocks on our door, and chasing anyone who walks past the house on the other side of the fence.
• Growling and occasionally barking at my girlfriend when she arrives, and he used to be totally fine with her.
• He's also started trying to get up on the beds we sleep on, something we've never allowed him to do before. Today I saw him approaching my bedroom, told him to come and he wouldn't, so I lightly jogged over to shut the door and he started barking at me.
• I also was patting him on his bum / back legs, which he usually likes the other day, and same thing - aggressive barking and snapping at me. 

Is there anything I can do to work on his aggression? We give him 2 big walks per day and feed him in the AM and PM. We've never used negative reinforcement, but I'm not too sure how to react when he gets aggressive. It's starting to bother me a bit that he's doing this, mostly because when he barks at us its far from a soft growl and usually scares the s**t out of me. 

 

 

[Moo]

Sounds very much like a possession type behaviour where he's trying too hard to protect what he considers to be his. I think a behaviourist is needed here, possibly some anti anxiety meds? But I know this subject has come up a lot here so there'll be plenty of people with experience to advise. 

[LBass]

I too have a hound who can morph into Cujo.  We've made a lot of progress over the last year working with a certified animal behaviorist.  I looked for a veterinary animal behaviorist because my hound is also blind and I wanted to understand the impact of that condition on his snarling, lunging, and growling.  I used the website of the appropriate licensure organization to find the right person.  The behaviorist I worked with was not local to my area but we worked together very easily using Zoom.  A great and productive experience.

Recently, I've been working with an animal communicator as well --  don't laugh, because that is really helping me "fine tune" a couple of remaining issues with Nate.