This sound like it has gone on a very long time. Since you really have no control at all over him we will have to approach this a little differently than normal. Usually I would suggest a muzzle and keeping a leash on him but that does not seem like something he will allow at this point in his life.
What I think you will need to do is start with some obedience training. I know you state that now he is unsure about treats and at this point may bite your husband. Therefore, it will fall to you to work with him on training. You will not be able to use any sort of reprimand at all at least initially. Your dog not only thinks he is the boss, he actually is since he now does nothing you ask him to do and makes the rules pretty much in areas where he is allowed. Obedience training my help that situation but it won't be a quick fix. You will need to work with him on simple commands first.
The following site is helpful in helping owners train their dog. Be sure and click on the link to the page on obedience at the bottom. and links on subsequent pages leading to detailed instructions.
Training works best if you train at least 30 minutes a day (two 15 minute sessions). I would start making your dog work via the Nothing in life is free program (NILF). It is outlined below.
I suggest that you use a treat like paper thin hot dog slivers or chic***** *****vers as a high value treat when attempting these training methods. Dogs who obey a command become just a little more submissive to the person giving commands each time they obey. This is true even if they only do it for the treat. This would hopefully get the dog obeying at least some commands though you won't have much control for at least a few weeks.
Once you have a few commands down pat, you can start having the leash around him even though you don't try and put it on him. If he is like most dogs, the special high value treats will get him close to you and the leash. You want to get him used to it being around. You will do the same for the muzzle. You need to gain his trust again. As he learns more commands, you can attempt to get a leash on him. You will want to take it back off immediately. This will help him realize that you are not trying to use the leash to control him. You will repeat this several times a day until he will allow the leash.
Continue the obedience training perfecting each command in turn. The next step will be getting him back used to the muzzle. Usually you put the treat through the muzzle so the dog needs to take it from inside the muzzle. Once he is used to that you start making him put his head further into the muzzle to get the treat until he is actually resting his head inside the muzzle for the treat. Then you would hold it closed like it was snapped on but release it immediately until he is used to the muzzle and allows its use.
By this point you should have some control over him. At this point you can have your husband start working with him on commands. Since he'll be getting those same tasty treats like he was for you and he knows the commands, it should go pretty well and he'll learn to listen to your husband as well. It is going to be a long process and I'm not sure I would ever trust him around your children or even strangers without a muzzle on.
I do think that you need to have him tested for hypothyroidism to rule that out as the cause of his aggression. Read more on that here:
I do understand that a mobile vet may also have a problem examining him and running tests but you could at least see if there is one near you. The following site may help you find one. Just put your zip code in under house call vets and press enter.
You should also consider a professional in person behaviorist. You should be able to locate one near you using the following site:
Unfortunately, you may not have a choice but to euthanize him. I don't like to see it done for behavioral reasons but if he is unable to be controlled by anyone and professionals are unable to bring about a change in his behavior, you may have to in order to ensure your children's safety.
I hope this information is helpful to you. If you would like any additional information or have more questions please don’t hesitate to press the reply to expert or continue conversation button so I can address any issues you still have . If you do find this helpful, please take this opportunity to rate my answer positively so I am compensated for my time.