Yellow Lab Pup

Question
Thanks for your quick response. One more question, if you don't mind! My son's girlfriend has a 2 yr old Min-Pin that she wants us to adopt -- she lives in an apartment and is working 2 jobs, so the little guy spends most of his day in a kennel. He's sweet but has been extremely excited and, well, crazy-active, the two times he's come to visit. My son claims that at home he is a lap dog and pretty laid back. Here's the question: we really want the Lab, but I don't  mind adopting the Min-Pin also since he could use an active home with a big backyard and he is a cute little guy. He has never been around other dogs, though, and I'm wondering how he and the Lab pup are likely to get along. What is the best way to introduce both of them into our home with the least amount of stress? Both are males; the Lab has been neutered and the Min-Pin will be neutered before I adopt him.
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The text above is a follow-up to ...

-----Question-----
Hi - we've found a puppy through a local rescue org that looks to be a pure yellow lab in every way. The only exception is his legs which seem short and at 4-6 months old he only weighs 28 lbs. This leads us to believe he is probably a mix. With no more info than this, is there any way to estimate what he will weigh fully grown?
-----Answer-----
Well he's still only about half way grown-around 5 months or so,they say to double the size the are at that point,so probably double the size he is now is what he will grow to be

Although sometimes it is impossible to say exacally how big a puppy will grow esp a rescue,but even dogs that are pure bred,you often can't tell until they are full grown

Answer
Well the best way,is to have them first meet in a park,or some place that neither of the dogs live at or consider 'there's' Just have them slowly meet by sniffing noses ect then you can let them play if things are going well up until that point

And it's a good idea for a while to put them in different rooms or crates when you are out,just in case they decide to fight when you are not there