If the snake has a severely V'd spine, I can see why it might not want to eat whole food.

If I were you I would probably wait for the Vet and ask them to show me how to tube feed the snake. I know I wouldn't even want to risk the chance of hurting an already damaged snake by feeding them the wrong way.

I once allowed the guy I bought my newest snake from to force feed her by shoving a mouse down her throat. I was new to the snake world and even then I didn't like watching and allowing him to do that. When I got her home she threw it up. I never will allow force feeding like that again. Complete waste of a good mouse and traumatised Sitka (the snake).