Small Female Siberian

Question
Wanted to get your opinion on a young pup that i have.  I recently got a female Siberian from a breeder and her weight is very low.  She is currently 5 months and weighs 15 #'s.  This is the second dog that I have gotten from this breeder and the breeders dogs have outstanding pedigree.  Almost all champions going back 4 generations.  This past week I received my pup's pedigree from the AKC and found that both of my female puppies parents have the same father. I called the breeder to find out if this was a typo and was informed that this was intended as a form of line breeding.  I have done some research on inbreeding/line breeding and there are mixed theories depending on the experience of the breeder, etc.  In your opinion should I be concerned about the size of my dog?  i weighered her last night and she weighs 15.5#'s at 5 months which seems pretty small.  My male Siberian was much larger at this same age. Any advise that you have would be appreciated.

Answer
Tyler,

Let me know what kennel that is if you don't mind (you can send in a "private" question if you'd like).  I know a lot of the breeders and can at least help there.

First, line breeding really is an accepted practice in purebred dogs.  It is difficult, but breeders who have been around a while are often quite successful at this.  If the breeder has a long history and champions in the line, it's probably not a huge issue.

If, however, the breeder is "trying" things out, it can cause issues.

Keep this in mind as far as your dog's size though:

1) Females are smaller than males.  (obvious, but just a reminder)
2) Adult female size should be around 20-22 inches at the shoulders when full grown.
3) Adult female weight should be 35-50 lbs. when full grown
4) Siberians usually stop growing in height around 10-14 months of age - weight around 16-24 months of age.
5) Puppies should steadily increase in weight over a monthly period.  A week of no gain, or even a small drop in weight at this age is ok, so long as it is normalized over a longer period (a month or so).
6) Puppies grow at different rates - even when closely related.  One pup might go through a growth spurt at 4 months and pack on some weight, another maybe not until 6 months.  As long as you see consistent weight gain and growth, there is little concern.  Some months are more, some are less.

15-16 lbs at this age is light, but the dog is about 50% of a recommended adult weight - which isn't bad.  If I had to make a blanket statement here, I would say a dog should be closer to 60% of the adult weight at this point, but again, each dog grows differently.  I wouldn't be overly concerned at this point.

The other possibility is abnormalities (perhaps caused by recessive traits being expressed due to line breeding, perhaps just a fluke) that cause a smaller dog.  In any case, if she is healthy and happy, it may just be a dog that isn't fit to continue breeding the lines, but for a pet, no problem.

Let me know the kennel or pedigree and I can help give you some additional background.