breeding size smal dogs

Question
Hello
I am a small breeder of shih tzus. Last year I purchased a male shih tzu to breed with my girls . His parents are 5 and 6 pounds. I did see the parents.  Well he grew up to be 12pounds hes not huge but very stocky. I am a little concerned as one of my girls are very petite and weighs only 7 pounds and i am not sure if it would be safe to mate him to her.  He did produce a litter to my other girl recently and I didn't notice a drastic difference in size. I am going to speak with my vet but I would like your opinion. when I look at them together he doesn't seem that much bigger than her.
thanks
Lisa

Answer
Hi Lisa

Males tend to be larger than females regardless, and a 5 pound weight difference should be fine.  Just viewing the parents isn't always enough, a pup is the product of at least 3 generations on both sides of it's parents.  So your little guy could be a throw back to a larger dog in his pedigree.

HOWEVER, I would not feed your female puppy food when she's pregnant as some vets recommend.  I would wait until after she whelps.  Puppy food has lots of fat and encourages the pups to grow bigger.  

Good luck.