Nope . . According to Willis' GSD:A Genetic History, heritability of wither height is approximately 65%. This is a polygenic trait that can be strongly influenced by environment. Caloric intake, amount of exercise, supplementation, and various other factors all contribute to a dog's eventual size. I personally believe it is very important to keep pups lean and fit. This will benefit them greatly in terms of joint health and longevity.
PAM Guardyan's Gavin, VCD2, CDX, RE, AX, AXJ, AXP, AJP, TD
PACH Guardyan's Helki, CDX, PCDX, RA, MXP3, MXPB, MJP3, MJPB, CGCA
Guardyan's Kamikaze BN, CDX, RE, OAP, OJP
Guardyan's Kricket BN, CD, RN, NAP, OJP