Why are some dog breeds more susceptible to different health problems and have more inherited diseases than others?
As far as I know, different bloodlines of the same breed can have really different health conditions, from being robust to serious inherited diseases. It's difficult to answer your questions when we don't even know the exact breeds you're talking about.

I agree with Ruslana. It's usually the genes of a certain bloodline. Much like the genes work in humans.

It's all about the genes... and within the same breed, health problems are more apparent in some bloodlines than others because some breeders would rather pump out profit or win that championship than breed for health and soundness... while backyard breeders often don't have a clue Emotion: wink