You, like most other parents, would go ballistic. So go ballistic. I understand that this is your father-in-law, but if some stranger off the street treated your dogs this way, would you bite your tongue?
Treat him the same as you'd treat anyone else. Let him know that he might not like dogs, but you and your family do, and to you they are members of the family and valued property at the same time. Let him know that if he cannot respect your home, your family, and your property that he will no longer be welcome at your home... but you will be happy to visit him at HIS home when your schedule permits.
Moreover, you don't have to tolerate that kind of rudeness in your everyday life. If he wants to be that way about your dogs even after you've talked to him, you need to put your foot down.
I am certain your Father In Law is grieving the loss of his wife, and is coming to see you because he does not want to be alone. Where the dogs are concerned. You need to inform him, just as you stated, you have never asked him for anything, and let him know he is welcome in your home anytime, but the dogs are part of your family and it will stay that way whether he likes it or not.
Also tell him you do not want to hear any more negativity about the dogs. Do not let him yell at your children because of the dogs. If he cannot accept your home the way it is, maybe its time he began visiting somewhere else.
If he has no other friends, there are churches all over the place that would welcome him. There are also Senior Centers where he can be around folks his own age and do things together with them. But set the record straight.
Your husband should do it, but if he won't, if it were me, I would. No ifs ands or butts about it. He is not the one paying your bills.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.