Bloodhound Man Trackers Inc.

Bloodhounds are PROVEN (they are not certified).  
A very important difference. ​

PROVEN:  
A Bloodhound is "Proven" by training records, the cases worked, with a confirmed track or find.
"Proven" means the dog does the skill over & over again (not just on one day for a certificate).
See Colorado State Law for Bloodhound Testimony.

CERTIFIED:
A dog is tested, usually once a year in a skill.

The dog may or may not be able to do this skill again in real conditions in the real world.
Certification is done for all other (non-bloodhound) breeds.

Colorado Bloodhound Law 
Supreme Court  State of Colorado
Brooks - v- Colorado No 97SC758

BLOODHOUND:
 Bloodhound is of a breed characterized by acute power of scent.
 The Bloodhound must be a purebred.
 The dog has been trained to follow a track by scent.
 The dog was found by experience to be reliable in pursuing human tracks.
 The dog is given the scent of the person to be tracked.
 Tracking efforts took place within a reasonable time given the abilities of the animal.