My dog of 15 years who passed away today, was like this dog a large stray and afraid of people, someone probably abused him. (He was terrified of spray cans).
I found him digging up grass and eating it, he was so hungry.
I got him to come to me after leaving food out and walking away, by doing what dogs do.
I laid down on my back in a submissive position and after a while of feeding and eventually petting him I was able to get in my cars backseat and lay down with the door open with more food and patience, and he got into my car layed down with me and ate,and I petted him again for a long time then slowly closed the door and climb into the front seat, and took him to the vet, and then home. He slept curled above my head the first night, he just needed a safe haven.
My loss is too fresh to do this right now, but if there is another Big Doggie lover out there other than me willing to take the time to tame him from my personal experience it can be well worth the effort.
Please do not call 911
I had a friend who had just given her dog a bath and her kids let the dog out of the gate in Cincinnati Ohio and a neighbor called 911 on this big dog, and the responding officer found him in the ally and shot and killed him. I knew this dog he would rather give sloppy kisses than any thing to any one of any size.
So please do not call 911.
Call a shelter and give this dog a chance at finding a good owner.
Thank You