I'm inclined to say euthanasia is the right answer, as I am always hesitant to suggest trying to place a dog with a bite history. The few people who can probably safely manage such a dog are most likely not out there crossing their fingers that they will get the chance to pick up someone else's problems. Finding the right situation is incredibly difficult, and the risk that the dog could wind up worse off is always there.
I 100% agree. I almost euthanized my Jack Russell last year (I've talked about it here before). At the last minute I got an appointment with a board certified veterinary behaviorist (more on that in a minute). We got some invaluable information of behavior modification, and even though he is very advanced in obedience (CGC, TDI, etc), he had absolutely no impulse control and was an extremely nervous and fearful dog. And I don't consider myself to be inexperienced with dogs by any means, but I now truly believe that dogs are capable of having "issues" just like humans are, regardless of their upbringing.
Without the BCVB he would be dead. I would not (and will not) rehome this dog, it would irresponsible in my opinion. We are in full on maintenance mode, and everyday is a lesson in something. It was a commitment we made when we decided we wanted him to live instead of being put to sleep. Dogs like this cannot be "cured". They can, however, be managed. In certain situations where he has known triggers he can never, ever be trusted. For us the biggest mystery was pin pointing the triggers and learning better ways to deter the behavior before it escalates. It seemed, sometimes, to come out of no where. This is where the BCVB came in.
Surprisingly, the most unlikely tool for us was our electric bark collar. I had purchased it shortly before contacting the BCVB, and she confirmed what I had observed - it broke the cycle of escalation. He'd bark when he saw someone outside, or a squirrel, or when the door bell rang. The more he barked, the more upset he got. Initially I would crate him or put him behind a gate to answer the door or go outside if there were people out there, but the incessant barking, and thus, the escalation of his frustration/fear would become more and more and more intense until finally one day he got through the gate and the front door (my other non-aggressive dog had opened it, mostly because I was lax in closing it properly, thinking the aggressive dog was behind the gate) and he ran down the drive way and jumped INTO a fedex truck trying to attack the driver. The obvious question here is whether or not we worked on exercises to train him to wait at the door, etc. The answer was yes. But true to a nervous dog with NO impulse control, obedience commands meant squat when he had his sights set on something. There in lied the problem!
The reason the collar worked for us is because we don't want to punish a dog for doing what it does, which is barking (and is the fundamental reason why dogs who bark in the absence of other behavioral issues would not be good candidates for an electric bark collar), but to interrupt the process of escalation. It brought him back to Earth long enough for us to introduce a reward for non-impulsive behavior, where as before I was so focused on stopping the behavior, unsuccessfully I might add, that there wasn't a break long enough for him to rewarded for the behavior we DID want. Which was quiet, calm, controlled, etc.
And it worked. And I'm happy to report that other than the battery that came with the collar, it hasn't been replaced it's been used that infrequently.
But before you run out and try aversion training, please consult with a professional though. Which is what brings me to the topic of "behaviorists". There is a HUGE difference between trainers and behaviorists. Many trainers are knowledgeable in animal behavior, but to be an animal behaviorist as recognized by the American Veterinary Society of Animal Behavior and the American College of Veterinary Behaviorists, you must first be a DVM and complete a residency with 200 cases under the supervision of a mentor approved by the American Board of Veterinary Specialization.
If you are paying a pet dog trainer who claims to be a "behaviorist", you are being robbed. (In my not so humble opinion.)
To recap:
* I do not think dogs with a bite history should be rehomed.
* I do not think dogs with a bite history will likely ever be "cured", but rather will require an intensive and interactive maintenance plan. Deciding whether or not you are equipped to make this commitment is an integral part of deciding whether or not euthansia is an option. Sadly, euthanasia is not solely dependent on the dog, but rather the treatment options available that are likely to work (or not work). That depends entirely on the handler and is something you'll (or the owner) will have to come to terms with.
* Said commitment is precisely the reason rehoming a dog like this becomes so difficult, running the risk of becoming a bigger nightmare as opposed to solving the problems.
* Trainers, while knowledgeable in behavior, are not behaviorists. Shop for a trainer wisely.