On a bike ride this morning I spotted a cat sitting at the side of the road whose face was badly scratched and sore- the front of his face was ok but from the ears down there was no fur and it was scabbed and bleeding. I had to come home to drop toddler dc off then went back round and it was still in exactly the same position. I tried to approach it and it wouldn't let me but didn't try to run away. It is awake and sitting but didn't seem to be registering my presence at all.
The RSPCA won't help because I can't confine it to my house or an outbuilding (I have a cat-hating dog, no outdoor storage and no way of catching it even if it would let me!) there's nobody else nearby that would help me 
Is there anything else I can do? It's a ten minute walk away but I'm going to go back shortly to check on it again.