labrador doesnt want to play

Question
We have a 2 year old female black lab. She is the most WONDERFUL dog , but lately we have noticed that she doen't want to run and play with any of her buddies.She will just stay near me or my husband. She is not mean or nasty to any other dog. We have known for awhile that she doesn't seem to like a "pack" of doge, does much better with just one. Wonder if we should send her to a "play" group again. Tried it but she seemed not to want to go and then when we picked her up ,it was like we had left her for a very long time.I know labs are very loyal,but we would still like her to have fun with other dogs.In another words is this normal for a lab at this age? I was expecting it when she got older.She is the best dog in every way. Thanks for your help. kathleen

Answer
I think it really varies from dog to dog and I think females start to lose interest in playing sooner than the males.  You might continue to give her short periods to play with other dogs, but let her quit when she loses interest.  

It never hurts to have the vet check a dog when its behavior changes.