OCD Surgery for Quentin

I was given Quentin in November. His previous owner's said he came up sore once in a while. The first time I rode him he came up more than sore and I had x-rays done. We found a large OCD in his stifle. He is in a considerable amount of discomfort and I want the give him the surgery and a pain free life but the surgery cost is entirely out of my budget. I have saved for half the surgery and I am hoping I can fund raise the rest. Thank you so much to all my friends that care about animals.