Is it normal for my puppy to have one lazy day?

My puppy is a 6 month old border collie cross. She is quite active usually around 3 walks a day and plenty of play. Today though she has been sleeping and being lazy for about 3-4 hours. We went on a morning walk that was about and hour long and played for about half an hour. Is this normal? Usually she doesn't sleep this long. Have I been working her to hard or is something wrong with her health?

We all sleep in every once and a while. As long as your puppy is acting normal while awake and eating and drinking normal I would say you have nothing to worry about . If you notice this is starting to become a habit and she is sleeping a lot you might want to considering changing food for a few days before seeking medical help. Just remember, puppies sleep more than adult dogs. If you notice any other symptoms you might want to take a visit to the vet just to be safe.This is what a Vet would recommend other than bringing him in. He would also tell you to check for any kind of mucus discharges around the eyes and nose. Depending on your answer to that would determine weather the Vet is going to recommend bringing her in. Other than physical pain.

You should check with your dog's vet who can ask specific questions and probably help reassure you, but also be right on top of things if it sounds odd