You probably don't feel like answering any more questions so you might just think about these , have you checked for a Tick ? First things to go are the back legs , they can just manage to pee with a bit of help . The anti venom works overnight and costs $200 AU .
Also , with what you say about neck injury , is your dog on the chain . Would it run to the end of the chain to chase a cat or something . Sudden stop at the end could twist the neck .
If it were me , I would first check for a Tick , if no Tick , I would wait and see what the anti inflammatories did in a week or so .