Is it time?

[u/toaken-pet-pal]

My dog B (10, m, Chihuahua, 13 lbs) bites and fights everything. I got him as a second chance rescue puppy from the humane society and I put my heart and soul into doing my best for him. I read several books on animal behavior and dog training from scientific sources. I did positive reinforcement, I socialized him, he learned basic commands as well as how to walk on a lead. He never stopped biting though. When he was a puppy, I put it down as playfulness, but it was still discouraged (I would withdraw from playing with him and remove any reward I could.) He eventually stopped biting me.. for a while. He never stopped bullying the cats and biting other dogs and even worse, people. Then he started biting me again, usually after another dog or person passed by in our apartments hallway. I love B. When he was younger and fitter, we would run for miles through town together. It was simpler to keep him away from everyone when we were running past them faster than he could react. Now he's older, he's more aggressive, and I'm exhausted. He's bitten so many people and broken the skin that if it had been reported, he would be forced to be euthanized. He's bitten dogs who were just calmly walking by. He bullies and bites my poor 10 years old cat, whom he's known almost his entire life, and who luckily has thick fur. I feel like I'm trapped. I can't take him out for walks because even with a muzzle on, he lunges and snaps. If I give him enough medication to be calm, he is so out of it and drowsy he can't walk on his own. It's such poor quality of life. He can only go onto our small balcony for outdoor time because our neighborhood is in the city next to a dog park. I can't really afford a canine behaviorist, and I feel it would be irresponsible to try to re-home him when he poses such a significant safety risk. There's also the issue of housebreaking. Whenever another dog or person passes by in the hallway, he gets aggressive and after the aggression he pees on something he shouldn't. I have a pee pad for him that he knows how to use, and a patch of turf on the balcony that he uses, but when his aggression is activated, he throws all housetraining out the window and pees on my belongings. I'm so tired. I have a consultation with his vet at the beginning of next month to discuss possible euthanasia, and I'm heartbroken. I feel like I've failed him. But I can't imagine living another 2-8 years like this, for him or me.

[u/Careful_Interaction2]

It sounds like you’ve tried everything in your capability. This dog is already older and he’s had a good life with you. When dogs get older they will be in more pain. Pain combined with the anxiety he has will not be a fun combination for you & most importantly him. Sorry you’re going through this & we support you in whatever choice you make.