Adopted a malnutrishioned puppy

Question
Hi I have a question / concern. 3 weeks ago we adopted a 4 mo old GSD male pup. Average weight is supposed to be 40 -50 lbs at this age according to stats online. We took him to doc yesterday to me neutered and he only weighs 26 lbs and is 18" tall to his shoulders. The stats say he should be at least 21" tall at this age I have changed him to Purina food and been giving him a can of wet food a day as well as one cooked egg. I am wondering if his malnutrishioned puppyhood will affect his adult size, or is that more attributed to genetics. Is there anything I can do to ensure he gets to normal size quickly or has his growth been permanently stunted. Thank you for reading and is really appreciate Any advice u can provide.

Answer
Hi, sorry for the slow response. Congrats on your new BABY!

It is possible that he did not get adequate nutrition as a puppy, but this may or may not affect his size now nor as an adult.
You are right to be concerned that he gets the best care possible and I suggest using a large breed puppy formula food and adding some real meat and vegetables to his diet as well. You can mix just a little boiled or grilled chicken breast in his dry food for instance, or if you can steam green beans or baked sweet potatoes he will love that.  The egg is a great start
There are very good kibble products on the market- please read the ingredient panel on what you give him-_ Real meat should be first.  
Good Luck.  I know you will love him even if he is a little short :)

Karla Haas,
President and Founder Rudy Green's