I know Stray Rescue only takes care of the shelter animals until they are adopted or if it is a special medical case for the ones adopted from them. Call and they can give you some info of where you can get help. I know a few people were sent to Mizzou for low cost treatment
You could try the Vetenaty School of Columbia. I hear they might help you out.
Typically Stray Rescue provides some vet service to only the dogs they personally adopted out. But you could call them directly and see if they have resources/persons to contact.
Thanks! Your answer is awaiting moderation.