my dog did exactly the same thing i took her to the vets thinkin expense and operation time but they managed cut it right down and its grown again and fine now. until u get your pooch to the vets bathe the paw in salt and warm water and be careful of infection signs good luck
I would contact vet myself, or I would use super clue and be careful not to get the clue everywhere....superglue is used also on cuts just like a bandaid...
Maybe superglue the nail, and redo periodically, and find a way to wrapp the paw to give the nail time to heal and grow...
Or contact your vet...
Keep us posted on outcome,,,,curious to see how this goes...and welcome to the dog forum...