Re: I am having a hard time potty training 4.5 mo
I would start from scratch, as though he's an 8 week old puppy. Put him on a schedule that's in sync with his system (not one set by the clock). Crate him, take him outside, no free walking-around the house until you're positive that he's emptied his bladder.
Puppies should be taken outside IMMEDIATELY after they
--sleep
--eat
--drink more than a couple laps of water
--play
Are you taking him outside on a leash? Are you taking him to an area where he has to "potty" first before he can play? Is the area separate from other distractions (as much as possible)? You should be doing that. Puppies get sidetracked easily and playing is way more fun than pottying, especially if the human makes us go inside as soon as we've pottied.
Keep the leash short enough that the pup doesn't have much of an area to sniff around. (No flexi's). Don't walk around. Just stand there.
Whenever your dog is outside, as soon as he begins to pee or poop, repeat your phrase "Potty now," or whatever. Repeat over and over. Every time. This will help the dog learn a "trigger" for emptying his bowels and bladder (kind of like humans always have to pee when they hear running water). He doesn't get off the leash or play. He potties.
My puppy (like Barb's Dante) was a double-dribbler. He'd go, but he didn't empty his bladder completely, so he'd be back at the door whining to go again. So I learned to take him out, encourage him to "go." Then once he did, I'd encourage him to go again. Sometimes, he had to think about it for quite a while (he was often sure he did not need to, mostly because he wanted to play), but after thinking about it and being repeatedly urged to with the Trigger phrase, sure enough, he still had to go. (Yes, this was often done in the pouring rain or the middle of the night.)
I tell this story because a lot of times puppies think they know what's going on in their little bodies. But they're little, and they need time and encouragement to concentrate and see if perhaps they're not quite right.
Finally, my guy never remembered to "go" when he was on a walk or playing outside. He's over a year old and 100% housebroken. But he still often doesn't remember to "go" when he's having fun. After playing outside, he runs in the house, hangs out for about a minute or two. Then he gets this look like "uh-oh! I forgot something!" Then he either rings the potty bells or whines at the front door to be let out again.
So when he was being housebroken, if he Pottied then played for a while, I took him back out on a leash to "go" again. It was a merry-go-round of potty/play/potty nearly every time we went outside. But he figured it out pretty quickly.
I think the thing is, we expect dogs to know that when they're outside, they need to "go." It takes puppies a long time to learn that. Heck, when we let the dogs out before bedtime, my 14 year old beagle will get so involved in sniffing the yard at night (when the squirrels, raccoons, etc are out), that I have to remind her that she needs to go. Then she pees about 5 gallons and poops. If Dh lets the dogs out and forgets to remind her, the beagle will come back in without going. Then he has to take her back out, and she'll go. I guess she was planning to go 8 hours without relieving herself.
One more thing is the emotional side of housebreaking. Someone here once said that you should act like your dog just won the Nobel Prize when they go outside. But if they have an accident, you really need to be careful not to act angry or frustrated (or not let your dog see that you are). Your frustration (if your dog can sense that, which he almost certainly can) is just as much of a punishment as your reprimanding him. Even if you're the picture of zen, the fact that your Dh and children are involved, and it's harder for children to remain calm when their feet are being urinated on, may be part of the problem. Somehow, maybe, you can remove the kids from the equation for a while?
Housebreaking that becomes emotional can become an intractable nightmare. You want a puppy who really wants to win the Nobel Prize for you. If he becomes afraid of your reaction to his accidents, you may be making them worse. And this will seriously impede your housebreaking.