How often should a female dog be bred?

[Sherri, Sophie, Winston, & Kitty]

I noticed on my breeders website that Sophies mom is going to have another litter of puppies in July or August. Sophie was born on December 25, 2010. Isn't it too soon to breed her again? Just wondering...

[Jennifer and Jack]

Karen what age does HD start to occur in dogs?

[Karen, Jasper and Jackdoodle]

It can show up any time, from puppyhood on up. Severe cases will be evident earlier.

[DeeDee and Sheila]

Wow.  I didn't know this.  This mixing is kind of scary, isn't it?  AND I didn't know until I started looking closely at one breeder's site how often she was breeding the same dogs in a year.  And how young they were when bred.