I have always had dogs and rabbits
but will underline what some have already said
NEVER leave your rabbits unsupervised with your dogs..however soft your dog is
You can never know if the dog is having an off day, feeling unwell, or just maybe gets a bit grumpy with age..and if the rabbit moves suddenly on jumps on dog it could just be enough to make the dog snap
Anyone who leaves their rabbits alone with a dog is playing Russian roulette with the bunnies life
Also a word on cats..same applies really..although a small cat may not be able to kill a large rabbit we have heard of several sad stories this year where a cat has bitten a rabbit..once in play..and the wounds became badly infected,
cat bites are full of nasty bacteria ..in two cases the rabbits died
..so be very careful about your bunnies playing with your cats