I have been feeding an outdoor stray cat for some time now. He is about 20lbs. A neighborhood big dog attacked the cat 2 days ago. I heard the commotion and went outside and scared the big dog away.The cat was on his back and I was able to grab him before he ran away as he appeared to be really hurt. There was cat hair everywhere. He appeared to be in some kind of shock for the first 24 hours or so. He has 1 small puncture wound on front shoulder and many scrapes. The cat has been resting for about 48 hours now. I cleaned all wounds and the many tons of scrapes with peroxide, betadine and neosporin. I am giving him 50mg of Penicillin twice a day. He accepts very little food and water with assistance. His 3rd eyelids are not up and his eyes look clear. He is very tired and probably in pain from the swelling of his shoulder. I can't afford to take him to a vet. He has walked across the bed twice so I don't think anything is broken. He relieved himself on a bed pad made for hospital patients. What else can I do? No vet will look at him without money and I don't have it. Humane Society or animal control will put him to sleep as he is a stray cat and scruffy. Doing the best I can with what I have. Am I giving him the right antibiotic? Can I gave him aspirin every few days. I just checked and he in now sleeping on the floor. Please advise me as to what else I can do. Thank you.