Introducing my new adult lab to my other adult lab

Question
Hi! I adopted a Lab/Collie mix from the SPCA about 2 years ago. She has always gotten along well and played with other dogs she has met. Recently, my husband and I adopted another adult female lab. I have read that having 2 females may not be a good idea. Since bringing home my new 2 and a half year old lab my 4 year old lab doesnt seem interested in her or vice versa. They do not play together and generally ignore each other. I was hoping for a little more comradare. Am I rushing things, or could this not be a very good fit? Any information you can give me on introducing the two in an appropriate manner would be greatly appreciated.

Answer
As dogs get older, they play less.  At 2 most Labs still want to play with other dogs, but if she hasn't been used to having another dog to play with, she may not be very interested.  2 females are the combinition most likely to have problems, but quite often they do fine together.  Even if they don't seem to be paying much attention to each other, they may be enjoying having each other around.  Give them both plenty of attention.  In time, they may do more together.