I am with your neighbor, I hate dogs left alone which annoy all neighbors with constant barking, while their owner doesn't have to listen to it. It's less of an problem in the house, but huge problem in residential apartment building, so obviously you call cops to annoy neighbor to force him to do soemthing about it by police harassing him, not that because you would genuinely think there is animal in distress. If your dog barks at everyone passing around your house, there is something wrong with your dog and you raising it. If you can't take care of dog and raise it properly, don't get one.

To be clear, he doesn't bark at people walking by the house. He barks at people who walk up the driveway, open the gate, and walk towards the house. He didn't bark until the guy was a meter or two away from the house.

That's his job.

He was left alone in the house for an hour. I have video surveillance showing the neighbour skulking around on my property.

Sorry, this is the reason we got a dog.

If the neighbour had a problem with the dog barking, he could have asked me "hey, when I come on your property and walk around your house, why does the dog bark?"

why do you keep gate unlocked when nobody is at home then? seems like easy solution to stop people trespassing and annoying the dog unnecessary and if it was locked and someone was there he can bark as much he wants because nobody should be there, obviously this doesn't work for people without gate

It may come as a surprise to you, but I don't even lock my front door.

If the dog is inside the house, you can't hear his barks from outside of our property, by the way. Neighbour only heard him because he was right next to the house.

Easier solution: don't be an asshole neighbour.

Not sure why you want to regulate what I do with my house and dog, which isn't harming or annoying anyone, while completely missing the point -- the neighbour shouldn't be there.

And he certainly shouldn't have called the police for something that he caused.