There are sanctuaries that take feral and or aggressive dogs. There is one in Texas.
I have a male chow mix that has a nasty disposition towards most people, but he is wonderful with me. I don't take him out in public places because he is a risk. He is fine around most women but he does not like men.
If I had a dog that was aggressive towards me and was biting me, than it would go to a sanctuary to live. It's a personal choice I would make. Sanctuaries are equipped to handle dogs with aggression or behavioral issues.
As far as medical costs go, shelters have to raise funds continuously to cover vetting. If a dog has a condition and it is going to costs thousands and treatment won't cure the dog, than you have to make a painful decision.
We just found out my brother's wonderful dog Patch has Lymphoma. It cost over $1300 for diagnostics and he just started his chemo on mon. Treatment is very expensive and will hopefully put him in remission for a year or two. Only 10 percent of dogs stay in complete remission. Like I said, it's a personal choice to save your dog and spend this kind of money. 4951