What is good for bringing dog hair back?

My dog has lost a lot of hair and I have tried EVERYTHING! I need a solution fast because he's sad. And I might have to put him down. What can bring dog hair back, anything he can eat, drink, rub on, or even spray? I will do anything to stop him from being put down!

What condition does he have that he's losing his hair? Have you taken him to the vet? Before you start talking about putting him down, don't you think it would be a good idea to find out why he's losing his hair?Also, do you give him plenty of exercise? Sometimes, a dog that doesn't get enough exercise gets stressed out and nervous. Which can cause hair loss in a dog.

Talk to a vet if you haven't done so already.