All About Dogs by LowchensAustralia.com

You can enter the dogs in the following classes:

Puppy class: From 5 to 9 months. You can have a maximum qualification of "very good". You can't have any points nor go to the BOB from this class.
Young class: From 9 to 15 or 18 months. You can have an "Excellent". You can't have any points for the championship, but you can have the BOB.
Open Class: All dogs older than 15 months. You can have the "Excellent", and you can win the points. You can't enter that class if the dog is already a Spanish Champion. You can earn the CAC (point for National Ch.) or the CACIB (point for International CH. , in International Shows).
Champion Class: Only for dogs already Champions of Spain or another FCI recognized country. You can have the CACIB, but not the CAC.

Spanish Championship.

You need to win 4 CAC under 3 different judges. One of the CAC must be won at the Madrid (Championship Show) Show, which is held twice a year, or at the National Specialty Show. If you win at the Madrid Show, you need to have a qualification of Excellent in the National Specialty. If you win the CAC at the National Specialty, you need the qualification of Excellent in Madrid Show.

So we have a maximum of 3 Champion Males and 3 Champion females every year.

 International Championship.

You need to win 4 CACIB, in three different countries under three different judges. A dog can have the first CACIB at 15 months old, and the last one must be earned 12 months later than the first. So the minimum age for a dog to become International Champion is 27 months.