I have a 2 1/2 year old mix breed 45 lbs (hound, lab, etc...). Rescued him when he was 3 months old. In the fall of 2017 (around 1 year old) he started getting very aggressive towards and attacking my other dog after meal time in a completely separate room with no food around (25 lb spaniel/lab mix). We trained with a behaviorist for 2 months and then got recommended to a dog doctor who confirmed he has anxiety and put him on meds to control the issue (this was last February 2018).
Over the summer months of 2018 he got aggressive a couple more times and we upped his dosage. 3 Weeks ago he started getting aggressive again (we upped his dosage 10 mgs to 40 mg's total).
We feed him his food as well as my other dog...when he finishes his food he's hesitant to leave his bowl for a couple of minutes. He is then very much on edge and if he sees my other dog he stalks her if she moves. The other day he finished eating, came into our living room (our other dog was on the couch). He walked by her and then lunged at her and very aggressively attacked her. Thankfully neither drew blood. This evening, my wife and I were sitting at the dining room table and he was near us. Our other dog came into the room (15 minutes after meal time), he watched her intently and then lunged at her...my wife tried to grab his collar and then he focused his attack on my wife, until I gave him a quick kick in the side, then he stopped, sat and chattered his teeth. I told him to go in his crate (which he doesn't use hardly ever anymore).
Everything I find online is about aggression with food while the dog is eating (I can pet him while he eats and he doesn't growl). I can't find anything about Post eating aggression and my wife and I are near our breaking point. HE's a sweet loving dog with us and also cuddles with our other dog non stop, especially in the winter months. They also play with toys together every single day with no issues...I don't know what's triggering him and while we've been told muzzle training is an option, he's already a really nervous guy, I feel like a muzzle (even if trained to use it) is going to increase his anxiety levels.
Again, I've spent a few thousand dollars with trainers and also a dog behaviorist....Has anyone else dealt with this type of random post meal aggression?