dog laid out

Same thing happened to my bulldog the other night. I walked him in to about 30 yards and sent him in to a kudzu patch. It was a good hog about 220-230 and he was slinging dogs all over. After I tied the hog we went to walk back out and my bulldog just laid down and wouldn't budge. The hog cut one of the bay dogs bad but the bulldog had just one small poke under his chin. He is in very good shape and gets hunted a lot, but was pretty hot and panting bad. He's never been wore out like that after just one hog when I sent him from only 30yards. I cooled him off and got him to the truck but he seemed out of it the rest of the night and the next day. Now he is acting normal. Can yall expand on the neck injury symptoms, and if it is just temporary or should I put him up for a while?