Buddy’s Foot Surgery

My dog Buddy is a 13 year old golden retriever. he has been with our family since he was a pup and my kids were just starting elementary school.  recently Buddy got a foot infection that we thought our vet solved but it ended up going deeper and festering. seems he's got a virus and the solution will be amputation unless we can have the proper surgery done which will leave buddy with his foot in tact. we have loved him like a baby son but my wife was laid off recently from her job at the auto plant and we don't have the funds to both take care of bud's foot and send my youngest off to college. any help would be appreciated..