Help needed please with dogs and kitten

[Dizzykizzy]

My beloved cat died suddenly in September. Both of the older 2 dogs grew up with the cats and were happy around them. We also have a pup who was learning to respect the cat.
I wasn't going to replace her but we live in a very rural cottage and we quickly started to get mice in so we decided to get pup used to a kitten we should get one quickly. Kitten arrived in October, puppy plays with her all the time, sometimes a bit rough but the kitten seems to cope and instigates play herself.
The older 2 dogs are another story though. They just will not accept her, the oldest dog (the one who curled up from a pup with both cats) just gets evil in her eyes and has to be restrained, the middle dog is silently and deadly, opens her mouth and chomps. Kitten had a couple of scary misses but doesn't seem to have any sense around the dogs.
I have tried to introduce the slowly, used a cage at first then just held the dogs when the kitten was about but we are getting nowhere. Kitten lives in a room on her own as I daren't let her loose. She goes outside but the dogs just go mad at the window when they can see her and I have to make sure she is in before the dogs go out. We can't go on like this....no life for the kitten and the dogs and me are so stressed! It is nearly 3 months and we seem to be making no progress at all.
Is it hopeless? Do I need to rehome the kitten and accept that we can't have cats? Any advice please?
The dogs are HPR breeds (GWP and pup is Korthals Griffon).

 

[s4sugar]

Dog date with cat flap?

At the moment the cat is seen as an outsider.

 

[pugsandponies]

I had a similar problem when introducing a kitten to my two dogs. The pug cross was only a pup at the time, and she was fine accepting the kitten, but my Parson's Jack Russell was very unwilling to accept her, going for the kitten and displaying aggression towards it. First of all I wouldn't ever restrain the dogs by holding them, as you said you have done, while the kitten is free. This will only frustrate the dogs more. I'd try and continue having the kitten in the same room as them, but in the safety of a secure cage or pet carrier, for short periods of time, a few times a day. Do this when the dogs are relaxed/distracted - perhaps when they are playing among themselves, or if they have a bone etc. Completely ignore the dogs, turning your back on them, if they display aggression towards the kitten, and the second they relax or stop, really praise them and give them treats. Continue doing this over a week or so and hopefully they should begin to learn not to be vicious towards the kitten. However, if they really don't seem to show any progress, perhaps the kindest thing to do would be to rehome the kitten, for peace of mind. Good luck!