Jojo's Bone Surgery

Right after christmas Jojo started limping. He's a bit rowdy and sometimes leaps too far while climbing, I assumed he just hit it weird like he's done before and he'd be fine in a week or so. It didn't stop. He kept limping for about a month, not showing any real sign of distress, he ate, he walked around, he did everything normally. After that he started yowling, and hissing at us. Not always just a few times when we tried to interact with him. This was odd, he's very sweet and never vocal like that (Cries when hungry, sure, purrs? like an engine.), but even when he feels bothered the most you'd get is a peep from him to know he's begrudgingly letting you bug him. We assumed he was just grumpy over something. Then the anger came more and more often, hissing, growling at any hinderance to whatever position he'd put himself into. He was even yowling when getting up or moving on his own. This clearly wasn't him and this was clearly pain, I took him to the vet. They poked his hind legs (Where he was limping) and asked if they could take an X-Ray, just to make sure he actually didn't break a bone that had healed wrong, kinda a bummer for my baby but not the worst thing right? Turns out it was worse, its an uncommon bone disease that SPECIFICALLY occurs in young male cats who have been neutered, and its not even genetic, Jojo just pulled the short end of the stick on this one. The surgery estimate bill listed up to $2300 dollars, which will include his actual surgery, the anesthetic, the IV's before and after, and all the medical and overnight care he'll need. The pain killers we have for him now, just to keep him comfortable throughout the day are $60 for just a weeks worth. Our options are, get the surgery which will scar over the joint its eating and replace its function, leaving him able to walk and live normally, or let his bone deteriorate, leaving him in pain, leaving him to lose function of his leg entirely, and because of the strain, a very high possibility of arthritis. In the long run the surgery is cheaper and he'll have a higher quality of life. But we only have a short amount of time to get him into surgery because once his bone has completely deteriorated the surgery is void and can't help him. We don't even know at which speed it'll eat away the bone by, it's just the sooner the better. Since he's only been limping about 3 months and half of the bone is gone, I'm assuming 2 months is about the longest he can wait for it. Jojo literally means the world to me, I would take a bullet for him in a heartbeat if it meant he'd be okay. Knowing he's in pain right now and theres nothing I can do to fix it or help him anymore than I am hurts a lot. Any help at all would mean the absolute world to me, anything you could donate would still be more than I could possibly ask for. Please help me help Jojo