This might help, you really shouldnt evaluate a pup or its structure before the age of 8 weeks...Pat Hastings is a wonderful source, I ve spoken to her a couple times she stresses more often than not the pups conformation is in place at the age of 8 weeks. She does evalutations only two days before eight weeks through two days after eight weeks no later.
Litter Evaluations by Pat Hastings
This is an educational tool - an opportunity for you to learn what is correct and what strengths are needed in your breeding plans. Litter evaluations are more about which lifestyle is suitable for each puppy and which puppies belong in a breeding program than they are about picking show prospects.
also her video might help too!
http://www.dogfolk.com/puppypuzzlevideo.htm
Puppy Puzzle is the approach developed by Bob and Pat Hastings for the structural evaluation of puppies. It addresses both the parameters of the evaluation process, as well as how to evaluate for decisions and answers. The process discussed in this video has been used by the Hastings to evaluate over 250 litters per year. For years they have documented each evaluation and have been amazed at the accuracy of the process.
See what it can do for you and your breeding program!
hope this helps
happy holidays