It isn't pleasant, but the vets can put them under and trim the quicks way back. Not pleasant but if her quicks are so long to the point her nails curl, that may be something that has to be done, for her own comfort. If the nails aren't curling after being cut it isn't necessary though.
Secondly, WOW. I did NOT imagine it would be that bad AT ALL. Are you sure she didn't get her legs stuck under something? Those feet literally look like they were crushed... If that isn't possible, she is severely severely down on her pasterns, maybe try giving her some vitamin c. I thin dogs just pass any vit c they don't process so can't OD on it so to speak (but you may want to look that up to be sure) and I know they give danes with leg issues vit c. Did this come on suddenly or gradually? I've never seen something like that, unless it was dogs who were injured and not treated so they healed wrong. What she has is not the same as the link to the Great Danes Tracy posted as far as I can tell. Are her back legs at all affected?
Do they have Care Credit in Canada? Because I would really try to get her into a vet and get xrays done. Or even better get her in to see an orthopedic specialist. Thanks so sad, poor girl! That can't be comfortable.