I'm feeling calmer now. Now I've stopped shaking and kicking myself things are a bit clearer.
My main priority is to all of the pets. It's not fair of me to put what I want first. If it comes down to having to re-home Devil or the cat, then it's going to have to be the one I feel would fare best outside of this house.
If my friend would take cat that would be perfect. Cat has lived with her before. Technically he is her cat. We rehomed two kittens together, when we were living together. When she moved out she asked me to look after Cat until she found somewhere to live. She got pg fairly soon afterwards and Cat just ended up staying with me. Mine moved himself into the church shortly after dd2 was born and I let him stay. I miss him, but he clearly wasn't happy with all the changes and the Vicar was very lovely. Cat stayed put, no matter what we went through, so I am loathe to rehome him. I adore him. But I must do what is best for him and Devil.
If my friend won't take Cat and she might not as he has a bowel condition and she is in rented accommodation, then I need to speak to local rescues regarding which pet has the best chance of finding a new, permanent home, the quickest and I'll make my decision from there.
Neither of them are obviously re-homable. Cat is ten now and has a bowel condition. Devil is young but has a skin condition and has shown aggression to people and other dogs in the past.
That is just the what ifs. None of them might be going anywhere just yet. I am going to give Cat a few days or so to settle back down, then I'm going to bring each dog in separately, on a lead, whilst Cat is Whippy's crate and judge how they react. If I am able to distract them from Cat, then I have a chance of being able to train them and I'd rather try that option first. They can be kept separate or under constant supervision, but I need to know that Cat is comfortable and they're not going to suddenly turn on him in front of us.
Whippy and the grey are not really an issue. I am fairly confident Whippy was not very involved and that she wouldn't act that way without encouragement from the others. The grey is not mine, if she is the one who is causing the problems then the rescue can do some shuffling about and I will foster a more cat-friendly dog from them.
Cat is fine. He is scared and hiding in the window, but physically fine. The vet nurse said to bring him back if I need to and they can give him something to help him get over the shock, so I might take him back this afternoon if he doesn't venture out from behind the curtains before that. If Cat cannot settle down around the dogs then I need to look at my options wrt finding more suitable homes for one or two of them, but I am fairly confident he'll find his feet again soon enough.
I am fine, I have a few bruises on my leg where one of them bit/snapped at me, but they didn't break the skin so I am confident it was not malicious.
Dh is not making things easier. The dogs are now a danger to his children. If that is what they are willing to do to a cat what could they do to his kids? I have explained that unless his children suddenly sprout hair all over their body and start moving at high speed on all fours, then they are in no more danger today than they were last week and if that happens then frankly, we have bigger problems than the dogs
. I think he is using this as an excuse to get Devil out of the house 
Looking back I am still not sure what exactly happened. I was too busy panicking and screeching to pay attention. Cat has no puncture marks. Both dogs involved are bred to chase and kill swiftly, they are more than capable of killing a cat in nano seconds. I am thinking they just held Cat down as some sort of game, either way, it is not acceptable and cannot be allowed to happen again, but if it was a game and not malice I have a better chance of being able to train them.
Now after that mammoth post I and my sore throat are off to walk the hounds and buy Cat some mince 