And I see a variation in the numbers like some breeders, like Woodhaven Labs, sell their dogs at 7 weeks.
Everywhere else, some people say it should be 9-12 weeks.
So what is the correct age?
OK, you have two questions. The answer to the first is that the puppy needs to be properly weened. Otherwise, it won’t grow and will become sickly because it has no milk. Bottle-feeding can be done but is difficult and less nutritious, just like in humans.
Plus, the pup knows its supposed to be near mom and will pine away for her (pups aren’t too bright, but all babies want mom).
The people who are saying nine to twelve weeks say it because the mother (cat or dog) will teach their offspring “manners”. Dogs and cats that are taken from their mothers too soon are harder to train and socialize, and may have behavior issues IIRC. For example, a mother cat will teach her kittens to use the litter box and cover their poo, and other survival techniques after they are weaned. (If she knows them, that is.)
Puppies are usually weaned before 8 weeks, chowing down on puppy food, but it is important that they stay with their mother and siblings for socialization. Not only does Mom teach them manners and life-lessons, but they also learn from play with their litter mates. A good example is they learn that if they bite too hard , brother or sister squeals , and the play stops. This is important to keep in mind- if you are playing with a puppy and it sinks it’s needle sharp teeth in, yelp like a puppy, and 9 times out of 10, it will stop immidiately. 
Try it. It works.
Thanks for the tip. Although it would look very unmanly if I were to yelp like a puppy when one play bites 
Trust me on this one. The look from the dog is well worth it.
I ahve to agree with that. The first couple times you do it , they cock their heads so charmingly with their lips pursed. You just have to remember that as soon as you yip, the play STOPS. Just as it did when a brother or sister was hurt. They catch onto this SO fast, since it is what they grew up knowing.
I think that there is another reason - housebreaking. In my experience, a pup just isn’t capable of being housebroken younger than 8 weeks. 12 weeks is much better for this. New dog owners who don’t realize this can get frustrated pretty fast.
I adopted one of my dogs at five weeks old. She had been dumped at the pound shortly after birth, and was overdue to be put down.
She did have a lot of socialization problems, but I worked with her intensively, and put her in Doggy Day Care so she could play with other puppies and learn dog manners. Today, she’s a happy, normal dog.
Again, though, it was a lot of work, and I don’t think most new dog owners would be prepared for the dedication it took.
I’ll second the socialization take. Dogs pulled from the litter too early don’t seem to know they are dogs, don’t like other dogs, and tend to not have the skills to socialize appropriatly with other dogs.
As for the housbreaking thing, I’d confirm that as well. My dog left the litter at 13 weeks. Lived in a barn with mom litter-mates, and numerous other dogs. No human instruction at all. Basically, he was housebroken. He had only one #1 incident in my house, and zero #2 incidents…I gather from my dog owning friends that this is remarkable.
Some dogs naturally housebreak easily. The dog I refered to in my previous post was remarkably easy to housetrain. I think it’s because she never got used to eliminating wherever she pleased.
As a very young puppy, I took her out every hour at first (four hours at night), then gradually lengthened the time between potty breaks. Yeah, it was a real pain in the ass and disrupted my sleep-- akin to having a human infant!-- but it was really worth it. The best way to deal with “mistakes” is to prevent them in the first place.
My new dog lived with his litter in an outside pen for almost five months. He’s been a real challenge to housebreak, because he never learned to hold his bladder. I’m now treating him like a brand-new puppy, taking him out every hour until he learns.
Did you put her right back to bed after you took her out at night, or did you let her run around for awhile? The reason I ask is that my eight and a half week old dog gets very riled up after going outside, and I’m not sure if it’s reasonable to expect him to settle down to bed right after coming back into the house at this age. I asked this question in another thread, but didn’t get an answer, so maybe someone here will know.
I put her right back to bed, but our situation might have been a bit different. Because she was ill, Hubby and I took turns sleeping on the couch next to her box. When she whimpered or cried, we’d drop a hand down into the box and pet her to reassure her.
Where is your dog’s crate? If possible, it might be a good idea to put it next to your bed. Puppies of that age get anxious if they’re left alone, so if you’re nearby, it might help settle him down after you bring him inside.
You could put a chew treat in the crate with him, so that if he can’t fall right back to sleep, he’ll have something to do so he won’t keep you awake. (A rubber Kong filled with peanut butter works great.)