Fund Genghis’ veterinary bills

My name is Shane, my partner is Marvin and we’ve got the sweetest old man, Genghis: a 12yo Rhodesian Ridgeback. A couple days ago, amidst excitement to take his morning walk, G took a spill down some stairs at our front porch. He was immediately favoring his left hind leg, refusing to put any weight on it. Dogs get hurt and are generally quite resilient so we got him some puppy aspirin to help with whatever pain in hopes it would subside quickly. He’s seeming to get progressively worse; he is refusing to eat or drink as it’s a struggle to get to & from his dish and even simple walks around the apartment have ceased and he’s just laying in the same spot for the majority of the day. We worry if he continues to favor this one leg that he’ll strain his other legs & hips and cause more damage. Vet bills add up quickly and with a recent move to a new apartment, we don’t have the funds for an incident like this. We’re aware he’s an older dog but aside from this he is in great health and want to give him the best fighting chance we can. For all of this, we are asking for help - whatever you can provide is greatly appreciated