White Labs...

Please forgive the ignorance of this question, but I know absolutely nothing about dog breeding, and have always been curious about this...

I have on occasion seen Labs that were either white or so light yellow, that they appeared white. Personally I have always thought that they were beautiful dogs and would love to have one. But it's my understanding that this is undesirable for some reason and have even heard stories of breeders putting puppies down for being white.

Why on earth would people not want this? They're simply gorgeous dogs and there's no way you'll convince me that the color of a dog's coat is in any way detrimental to the breed. Certainly not more that inbreeding them to the point where hip problems are a way of life...

Kevin