SERVICE DOG NEEDS EYE SURGERY

My service dog, best friend, child Pancho desperately needs a surgery to heal his eye finally! He has a reoccurring ulcer that can only be fully healed by an ophthalmologist performing a surgical procedure on it. We live on an extremely low fixed income and I have absolutely no way to raise the $500 for it!,He's absolutely miserable, in the meantime! It has tears constantly running down and he can't open it for more than a second or two. For all he does for me, I have to way a way to give back to him! PLEASE HELP ANY WAY YOU CAN!