Please help dobby

We found dobby today after having broken free of his leash and running off 3 days ago. Since then it has been hot and sunny at times and pouring rain at others. Dobby is completely bald causing sever sun burns. He is very dehydrated. He is in pain from multiple lacerations, abrasions and other wounds. Several xrays were taken and thank go nothing was found to be broken. Several other conditions like a fever, hyperkalemic, and hypocalcemicwere found. They believe he has Addisons disease and that it requires treatment. They are charging $3000 to $5000 for 2 days of treatment we are asking fi $2000 so they can begin the treatment. Thank you to anyone who is able to help