so my neighbors upstairs recently got a puppy. a BIG puppy. and this puppy has a barking issue. that they apparently haven't addressed. i hear them raise their voices about other things here and there. but not once since they got this puppy have i heard NO! from up there

every morning around 6 am the puppy has a barking fit. and while they are at work/school, the puppy barks A LOT when he's alone. i've gotten into the habit or just reaching up and grabbing my ear plugs in the morning. and i can more or less tune out the barking during the day. but thats not the ultimate solution.

i have a sneaking suspicion that us moving downstairs (in november) with a dog, got their kids begging. but the difference is, jiffy is a tiny shih tzu! our apt is plenty of running space for him to tire himself out. there's also a pretty small fenced backyard, which is also quite enough space for jiffy. they take the puppy for plenty of walks on the leash, but i don't know if they ever let him run in the yard. not that i've seen. still only jiffy's tiny paw prints in the snow

i need to approach them about the barking issue. they're not dealing with it, and their impressionable baby is going to become a loud nuissance. the puppy is very quickly becoming a large dog. i'd hate to think that the dog will end up back at a shelter and possibly put down just because of poor breed selection/poor training.

how can i approach our neighbors? i want to be able to help them to train their dog and let them know that a few short leash walks might not be enough exercise for a dog of that size without being insulting. which is difficult, because things like NO! and execrcise seem like such an obvious thing! i support their right to have pets, but i feel like they are completely clueless, and maybe this wasn't the best decision.

does anyone have any experience with tactfully approaching a neighbor about an issue like this?