high energy breeds

I have just adopted a 6 month old Lab/Pointer Mix. She has bounced around from her original family to shelters and a foster home prior to arriving with us. Currently, we are getting her used to our schedule and working on finding her exercise limit to help smooth the process so she can be more...

I keep hearing that too much exercising can be bad for a puppy's joints. But how much is too much? I have a very high-energy 12-week old. She is golden-lab-collie mix, who looks like a golden-lab, but has energy demands of a collie. She goes bananas:dog-crazy: if not taken for a good long walk...