puppy barks all day while owners are away

When they put him in a crate, was the crate inside the house? I think the dog should be inside. Putting the dog through training classes isn't going to make him stop barking... It's interesting that, at 5 months old the dog doesn't have all its shots yet, but that's irrelevant.

Could they use baby gates and gate the puppy into a puppy-proofed kitchen, perhaps?

Also, he may need to RUN instead of walk. A tired puppy is a good puppy.
 

He shouldn't be left in the back yard. They need to leave him confined inside the house. The kongs and all of that are good but he should be getting that stuff in a crate in the house.

SOME trainers insist that a pup have shots all the way up to 6 months before they attend classes.  That's why the shots aren't 'done' yet. 

However -- he needs to be INSIDE.  No wonder the neighbors are complaining.  He also needs to be *****trained***** to a crate.  that doesn't mean you put him in there and walk away for 8 hours.

It takes a few days to train him to a crate -- you feed him in there, give him treats in there and generally make it an awesome place to be.  You let him out in short order (sometimes you don't even shut the door at first).  And you don't let him out when he barks -- but rather when he's quiet (and you may have to stand there and quiet him for a minute to GET him quiet).

You increase his time in the crate (make it worth his while -- give him his breakfast in a Kong or other think toys to keep him busy for a while). 

He may bark IN the crate but it needs to be IN THE HOUSE (or he is a sitting duck for anything from snakes to human bunchers who want to steal a purebred dog to sell it). 

But in the house you can leave tv/music/white noise on for him, you can leave him in a bedroom that's carpeted to absorb noise (with window treatments to also block noise). 

Mostly these people need to understand that training a dog is more than a couple of walks in a day.  He's not getting enough exercise and he's probably lonely.  I have to wonder if he's adequately housetrained if he's simply been put outside because he was a destructive puppy inside.

Someone probably needs to be coming home at noon to expedite this, or a dog walker can be utilized to keep him from getting stressed.

Why not invited them here -- so they can get some better ideas on how to train him.

also -- I would be getting this boy into a training class.  Maybe a class can be found (or individual training) that isn't quite so insistent on the 'rules' because otherwise this pup isn't going to have a home much longer.  These are the type of dogs who wind up in rescue because people really don't realize how much there is to training a puppy and by the time a problem of this magnitude develops someone in the family is usually ready to give up.

I'm not speaking badly of them  -- it's a problem that's all too common.  But he's barking out of boredom, he's barking out of loneliness  and fear.  Bringing him inside and adequately and humanely crate training him will help enormously.

Yeah... Rascal is generally a very quiet dog, but if he's alone outside, he's going to bark and whine and cry. He barks to say, "Hey, I'm outside, someone let me in!" and he barks to say, "This is my house, whoever you are outside the fence making noise, stay away!" and he barks to say, "I'm a dog and I'm bored!"

If he's crated inside he simply makes himself comfy and goes to sleep. That's because I've put a LOT of time and effort into making him think is crate is really a nice place to be. Feeding him in there, teaching him a command to go in there, giving him zillions of poofy pillows and blankets in there so he can burrow himself in nicely...

I think a lot of times people will leave the dog outside during the day "so it can entertain itself," but it really won't do that. Imagine yourself put in a backyard all alone, with very few things to entertain you but lots of people/things within earshot, versus being put in a small comfy room with a nice bed and some comfy blankets.

 Isolating a puppy outdoors is a prescription for creating a barking dog.  Do they have access to a dog day care facility where he could stay during the day (the play with other puppies would be great for teaching him to inhibit his bite, too)?

Try contacting a positive trainer in the area - some of them have adapted to the newer philosophy of taking dogs into training at younger ages, because the risk of being dead or turned in to a shelter from behavior problems (like incessant barking) is greater than being dead from disease.  Listings of positive trainers:
www.trulydogfriendly.com
www.peaceablepaws.com
http://www.clickerteachers.net/clicker/index.php