Hello,I am so sorry your little one is having trouble.I would love to help I just have a few questions so I can better assist you.
What breed is your dog?
Where are you located(city and state)?
There are several agencies that may have funds to help. You may have to call several of these as some may not be able to cover the full amount. You can apply for more then one program.
Here is one specific for back surgery
Dachshunds Needing IVDD surgeryhttp://members.rushmore.com/~dds/applyforhelp.htm
Here are some additional agencies that often help with this type of problem
Humane Society of Missouri 1201 Macklind Avenue St. Louis, MO 63110 phone:(NNN) NNN-NNNN/strong>Pet Care Assistance ProgramSince 1955, the Humane Society of Missouri has provided the public with veterinary care for animals. We have approximately 24 veterinarians and veterinary technicians that can provide the best care for your animals. The Pet Care Assistance Program helps to provide veterinary care for low-income pet owners.
This is a low cost clinic in Savannah but they may be able to help
Here are additional programs
Care credit may also be an option
I hope this has given you somewhere to start , please reply back if you have additional questions or concerns
Did you get a reply back from either of these. They do provide assistance for back surgery