Is this dog's situation an SPCA issue or a health department issue?

And which organization (in New Jersey) has more resources to help me help him?

Here’s the story: My apartment’s bathroom looks out on a small concrete run that belongs to my neighbors. They keep their dog in there 24/7, give him no walks, and rarely clean his run. Here’s some pictures. He barks semi-constantly out of boredom. Poor sweet guy – whenever I stick my head out the window to talk to him he acts all desperate for attention. Why would anyone get a dog just to stick it in a tiny concrete prison and ignore it?!! To torture their neighbors with the smell of dog shit, the constant barking, and constant feelings of pity for the poor animal?

I’ve tried to talk to these people – I would love to take him for walks when I take my own dog out. But they won’t come to the door to talk, or even acknowledge through the intercom that they are the people in the building who own the dog (I know they are because I’ve seen them through the first-floor windows and because the other residents of the building have confirmed this for me).

I’ve been hesitant to call the SPCA because I’m afraid they would probably take him away, and I think that he’d be euthanized (this area has an extremely high euth rate). He’s pretty old. I’d adopt him or foster him myself, but I have little enough cash for my own pets’ vet bills and I couldn’t in good conscience take on another dog at the moment. Am I wrong – would they be more likely to warn the people and educate them?

Or would calling the health department be more effective? These are truly unsanitary conditions for the dog, and I figure that even if they don’t care about the dog’s way of life they ought to care about mine because I’m human, and I get a dog-shit smell wafting into my yard and my bathroom all summer long. Would they just have to call the SPCA anyway?

My priority is helping the dog – I know I can buy a sonar gadget that’ll stop him from barking, and I can keep my bathroom window closed and just deal with it in the backyard.