I have been searching for days for a module or solution for how I can create a menu on my drupal website which displays ONLY categories which have had content submitted within them.

The site is: www.nicelittlepups.com.

I have created a category vocabulary called Breeds within which i have created terms for every dog breed on the face of the earth.

Users are able to log on, specify the dog(s) breeds, upload pictures and enter information with respect to the puppy(s) they desire to sell online. Rather than having a rediculously long list of puppy breeds in the menu, a menu displaying only the breed categories under which dogs have been submitted.

Ideally this menu would be expandable as well. In other words, the breeds would be collapsed into the letters of the alphabet, then upon clicking "A" for example, the breeds starting with "A" which have been submitted by users be visible. The breeds which have 0 submissions will not be displayed.

Is there any module for this? or Is there any part of any other module that would allow for this?
Is there any (relatively) easy way to create this myself?

This is one of my first Drupal installs. Indeed i am still learning, however i have done a lot of reading about its different aspects and modules, however i've not found a solution for this!
Any advice would be greatly appreciated.