Thanks everyone.
She was still walking pretty well yesterday but today she is in further distress, to the point she can barely stand. I got her to eat a little steak and gave her the metacam. Fingers crossed it does the job.
If she continues to not be able to walk we'll be going back. I guess since she spent most of the evening lying on a heating pad/electric blanket last night she is more than a bit stiff. But I don't want to ignore any warning signs of possible complications.
How long does it usually take for a dog to recover from a bad sprain? And what's the best way to manage things like toileting? She won't use a puppy pad but I loathe to take her outdoors to walk around in the slippery snow and single digit cold.
The vet also said she probably shouldn't use her little snow booties unless temps are very low because she may have lost enough traction to have injured herself.
She's asleep in her cuddly cup now, the poor baby. I wonder if that's really the best support for her back though. She was in bed with me all last night on my pillow.
Any other suggestions for making her comfortable and taking care of daily business like meals and eliminating would be most welcome, thank you.