Your otherwise normal dog is yelping in stress. I know many dogs out there who are perfectly in health and yet gives out that Auuuuuwwwww sound every now and then.
There is always some reason for this stress, maybe he’s excited to see another canine in the area or a cat. Or maybe he just doesn’t like being chained up. maybe she wants to go out for a poo.
Dogs yelp when they are left alone for long.
You have to find out the exact cause.
Sometimes there is some pain in the stomach due to gas. to recognize this pain, hold your dog and press every area of his body and see the reaction.
In case of stomach pain or pain in internal body parts, there is frequent whimpering, yelping in pain too frequently. There is too much of that auuuuoooo sound. Your neighbor might complain of this sound.
If you ever see your dog is yelping in pain or yelping is followed by trembling and shivering contact a vet ASAP.
Therefore, the point is that although you cannot always tell why he was giving this high pitched sound, he was trying to say something, and you should make an effort to find out what.