Help a heavily injured dog please

Hello everyone, I am a volunteer. I always try to help injured or dying animals. Last day, someone called me and informed about the dog. It was heavily injured. So, I admitted it into a hospital. Doctors checked it and told me about the total cost. The amount was about 500 US Dollar. I am a student and I am not stable now. So, I can give maximum 50 US Dollars. In this case, I need more and more financial support. So, please help me to gather fund and let me the dog alive. I have not any paypal account. So, I used another one. I am not very good at English at all because my first language is not English. So, Please forgive mistakes. Help me to collect the total amount of money. Thank you.