What would you do in this situation?

Please remember it's not the dog at fault here it's the idiot owner... The dog will ultimately pay the price for how it was raised by the idiot owner but isn't to blame for not being taught appropriate behavior.

I would follow up with the police and/or animal control in the next day or two and ask what is happening with the complaint. Does your city have a dangerous dog bylaw? If so it is very likely this dog has just become one with the attack.

I would also talk to neighbors about what happened so they can be on the look out for their children and pets. It may also help with getting this resolved as someone else mentioned.

In addition to the other answers (following up with the authorities and notifying the other neighbors) there are a couple of other actions you could consider, depending on your stamina:

1 - be always ready with a camera to take a picture of the dog off property and off leash. Speak with the authorities, continue to show them the pictures at various times (show up every time you have new ones with the documented date/time) and just become a pain in the ***. If you can get their attention and if you can find a pattern as to when the neighbor lets out the dog, you can insist a patrol comes by at that time or call them as soon as you see the dog loose.

2 - Another option (although probably not as well received) would be to sue your neighbor for the vet bills you incurred. Obviously, your neighbor is not a caring dog owner or a good neighbor so maybe he will care about his $ and the high cost of owning a dangerous dog (this is not against the breed, but about the handling).

You've already taken the 1st step by calling the police & filing a report. Once you get your dog to the vet you'll have vet records to back you up. Your neighbor should also be taking his dog to the vet... he's got to have at least some bruising or something from being hit with a 2x4. That will also show in your favor (how hard/many times you had to hit it to try to get it off your own dog, and it still wasn't enough).

If the police action fizzles out & nothing comes of it, get a lawyer.

Ask your neighbors if anyone else has ever had a problem with this man & his dog. You never know what they may tell you.

I have a similar problem to you and asked a similar question not long ago. Unfortunately, you can not make other people responsible caring owners. You can do things to protect your dog. It sounds like you may not have a side fence to your hard, enclose it completely so their dog can not get to yours when you are in your yard. If taking your dog to the front, check first to make sure the dog is not out first.

Check with your neighbours to see if anyone else has had a problem and ask everyone to complain every time they see the dog loose. By reporting it at least you have the first strike against the dog. Also speak to your local government council about the dog rules in your town, are dogs allowed off the lead at all? You may be able to report him in this area as well.

Just a note in addition, I found that it made my dog fear aggressive and I ended up having problems with her with dogs she did not know, so just watch her body language when out and about

Also, I keep a shovel by my front fence, those dogs come again I will be ready this time.

You have already done the right thing by calling the police and filing a complaint. I would follow up on it and talk to your neighbors and ask them to back you up. If they have children, they most certainly must be concerned that this dog may attack them. Maybe even get a petition and ask neighbors to sign it and take it to the police as evidence that you are not the only one threatened by this dog. You sound like a responsible person, and I cetainly hope your dog is OK.