Greyhoundboi

We've had our ex-rescue grey over a year now and in that time he's had some behavioural issues that we've weaved around. It's mostly his aggression towards other dogs, which mean we always have to walk him with a muzzle and can't approach other dogs. He also is aggressive towards humans he doesn't know, so now we have to keep our front door shut or our post gets hurled over the fence. Lately however he's started totally ignoring everyone but my dad. He adores my dad, and wines at the door when he hears his car pull up, and will listen to his every command, meanwhile he totally ignores everybody else. This becomes an issue when we try and walk him in the morning while dad is at work (and the word walk or sight of his leash is the thing that used to get him super excited) but now he just ignores it and stays in his bed. Even roast chicken doesn't tempt him all the time now because if he sees the leash first he thinks it's a trap. We're not really sure what to do, and its certainly making our dog a bit less enjoyable to be around that he is totally emotionless to all but one of us. Has anyone else experienced this and has some advice?

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.