panting

Question
Is it normal for large breed dogs ( ours is a white shepherd 8 months) to breath so hard after running after a frisbie for about 5-10 mins? We throw it from one end of the yard to the other to give him exercise and he seems to pant so hard.

Answer
Partly it may have to do with conditioning.  You may be over exercising him and stressing his developing joints.  Maybe limit the
Frisbee chasing until after he is a year old.  

Keep him lean too.  Your dog definitely should be narrower at the waist than the hips and chest. You should be able to easily feel the ribs, but not see them. Each dog is different. Standard recommendations are a good place to start, but each dog must have its food and exercise adjusted to its individual needs. Here is a link to a good illustrated guide, http://www.longliveyourdog.com/twoplus/RateYourDog.aspx