dog doesnt want to walk

Question
Hi ! I have a female yellow labrador who is now 5 months old. We are going to dog school every Sunday with her and she is doing very good. She sits, stays and everything. She used to walk real good, by our side. But about a few days ago, it's like she didn't want to walk anymore. At first, she looks excited to walk when we take her outside, but a few feet later she stops and doesn't want to go any further. Even if we call her, pull the leash... Nothing will do, unless we go back to the house. Then she seems happy to walk (because she knows she's going back to the house). She does not seem to have any injury, nor problems walking. She used to do just fine until 2-3 days ago.

What's going on ?

Answer
This could be several things.  It could be an injury you aren't aware of.  Is she as active as ever in the house?  If not, see the vet.  She could be in a fear stage.  As they grow up, sometimes puppies suddenly become afraid of things that haven't bothered them before.  If so, it is best not to push her.  Don't coddle her or let it stress you.  

You could try what I do with young puppies just learning to walk on lead that won't move.  If getting out in front and coaxing doesn't get a puppy moving, try dropping behind it and running by in baby steps calling ''Go, go, go!'' In a happy, excited voice.