First, let me say i'm happy to announce that as of about a week ago, Zack is officially house trained. He finally got it. He has given up using the wee wee pads, even though they are still sitting (wadded up) by the doors. He asks to go outside and he goes potty when he goes out. He was about 20 or 21 weeks old when this happened decisively. Before that, he didn't get it. He usually went potty outside, but mainly because i watched him pretty closely and put him out frequently (i would pick him up and put him out, carrying him affectionately), and also because of the use of the crate, so that when he had been in the crate overnight or while i was at work for 4 hour stretches, then when i put him outside, he was most likely to pee, because of the long wait.
He consistently used the wee wee pads in doors, and i was worried that he was getting the message that it's ok to go in doors, but he has given up the wee wee pads. I won't be surprised if he makes future mistakes, but i can see that he is getting it now. yay.
so, i attribute this successful outcome to:
catching him in the act of when he on rare occasions peed on the rug instead of on the wee wee pads, so i could communicate that this was not desired behavior, by giving a disgruntled expression and putting him outside and saying "Pee outside."
About crate training, i had heard that dogs are clean animals and will learn to control their bladder and bowels because they don't want to soil their living space. So i think what happens is, as they get older, their concept of their living space expands, and eventually it encompasses the house they live in, and eventually they transfer their crate behavior to the whole house.
I didn't put a lead on Zack when i took him out in the backyard many times a day, but the yard is very small. I always went with him in the beginning and watched him because i wanted to clean up poop right away. I read in a book cleaning it up right away encourages the dog to use the same area. My backyard has ivy and foliage, and if i'm not watching, he could do it in places i would never find. But he tends to go in places where i can see him even when I let him out by himself now.
Anyway, i would say that overall, house training went pretty smoothly. But this is one reason why i chose to get an older puppy (he was 16 weeks when i got him)--because i have a day job and it helped that by the time i got him, he was somewhat crate trained. And his consistent use of the wee wee pads indoors minimized the trauma. Him having diarrhea and very soft stools during the first couple of weeks when he was still going on the rug and not always hitting the wee wee pads made things harder than they would've been without the diarrhea (thank goodness for natures miracle) but generally, house training progress was pretty steady.