My 11month old English Bull Terrier

Question
Hi there,
I'm hoping this site can help me, as i have literally searched every where and asked everyone and ofcourse gotten totally different answers from all the different places. My mom bought me a Pure bred English Bull terrier pup, i went and chose him, not much of a choice thou since he was the last pup left, ofcourse being so damn cute it would have been hard for me to say, "oh i don't know if he was the biggest" i didn't care, i fell in love with him straight away. and he seemed like a sturdy pup for the first few months, nice size head and stocky, but lately he is looking lanky, not thin to the point of starving but he lacks muscle, and he is lacking in energy too, i went on a 5km run/walk with him (storm) and my other bull terrier (she is a cross thou with staffie) - she is 4 years old (lexi) and happy and healthy, anyway, and lexi was excited and fit and more than able to keep up, storm on the other hand was panting frantically, lagging behind after a strong start, if we stop for a second he would fall down to rest and then get going by leopard crawling and then only get up, by the finish line he was FINISHED - as in crawling and i had to carry him, he wouldn't stand, lexi was FINE, still had energy to jump on me to get my ice cream. This was about 2 weeks ago, since then I've been worried that he isn't getting the right diet and that he is too small for his age, i horribly regret following the breeder's advice on what to feed him as now I've found out i may as well have fed him bark. at the moment his is weighing in at 15.78kg and isn't very tall or muscular at all, he is looking more and more like a runt. he is such a loving dog, and really has no problem with hunger for food or love.
Please help me in giving me a guideline as to what he should look like and weight at his age ( 11.7 months) and if he is under weight what can i do to bulk him up and get his stamina levels up. I don't want to be embarrassed every time someone asks how old he is on the beach and i tell them and they are shocked at his poor size.
i also don't want to be cheating my dog out of the best nutrition and life he could have.

PLEASE help me out with some tips , advice what ever you can get, even on exercises i can do with him.

thank you...  

Answer
Hey
Poor guy and poor you too! Definitely sounds like you have a problem. But either way starting a dog, any dog on a run like that without proper conditioning is dangerous. Just like starting a human on a long run just out of nowhere is dangerous and usually impossible. Lay off the exersize until you find out what is going on with your boy. Have you had his thryoid checked? How about his heart? Blood tests for diabetes? There are TONS of things that can cause problems like this, even problems with liver, or pancreas. I don't know what you're feeding but for ANY dog you need to stay away from any food with by products, corn, wheat, soy, and chemicals. Wellness, Natural Balance, Flint River, Canidea are all good choices. Stay away from anything you can buy at wally world or the grocery store.
Get a complete physical with blood work up etc if you haven't already done so. I think there is likely a physical problem causing this.
Good luck
Cindi