Shadow and Etos

Shadow and Etos were the best of friends always together were ever they went.. As soon as etos came in thru the back door, behind him was shadow. Etos inviting him in the house all the time to have supper with him and relax, my little etos is very friendly and not mean at all. He is a very curious cat and very nosy, one day I was painting and wanted to know what I was doing.. till the point that he put his paw in the paint and had paint all over him and the carpet!!! I had little paws down the hallway in the carpet and on my bed, it took me awhile to clean it all. One night something happen to poor Shadow, my husband opened the front door and there in our front door poor shadow lay. He dragged himself all the way to our front door, he was dragging the whole bottom part of his body. I guess someone ran over him, I checked him all over and didn't see any tire marks or anything on him. I made him comfortable and made a bed and kept watch over him, I contacted a vet hospital in hopes they would let me know what to do. I also figured I would take him to humane society or somewhere he can be helped, You see he was an outdoor cat and didn't want to stay indoors. He was dragging himself down the stairs and I fed him a little, then I noticed he was bleeding. I called the vet hospital and they told me they could look at him and it might cost about 800. to keep him over night and see if they can help him, but was not guaranteed he would walk again or make it. I made the decision to put poor shadow to sleep, you see I didn't have that much money to take care of him and I really regret it. Here I was going to the vet hospital at 3am in the morning in a not so good neighborhood, my poor oggie was sitting with me wondering where I was dragging her this early in the morning. My Etos has never had a friend like shadow :O(