Loving Dog Left for Dead! Please Help!

A HELPLESS ANIMAL NEED YOUR HELP! 3 days ago my neighbors moved out of their house without warning and left their sweet dog to starve to death in the cold. My boyfriend discovered their dog on the side of their empty house digging through trash they left behind looking for food, he was skin and bones and appeared to have not eaten in days. We immediately brought him over to our home and gave him food, water, and a place to rest. He is incredibly sweet, mellow, and kind despite being abandoned. Although he is very weak and does not want to raise from his bed unless absolutely necessary, we fear that besides being incredibly malnourished he may have medical problems from long term neglect and being out in the freezing temperatures. I have absolutely no idea what type of treatment he may need or what it may cost and unfortunately do not have the funds to cover a vet visit on my own so any help at all is appreciated, any extra money accumulated will be donated to an animal charity for other animals put into similar situations. I would be happy to answer any questions or concerns about the situation. Thank you! UPDATE: We hit our goal! Thanks to a very generous donation that topped it off, I also want to thank everyone who donated as well, I posted a video with a big thank you in person! He has an appointment to see a veterinarian tomorrow in town, and I will be posting pictures and information on his condition when I have them! Thanks again everyone!