Earthdog is test that provides insight in terrier's hunting ability, simulating typically terrier hunting situation by making artificial lair at the end of which is a cage with rodent inside of it. Dog's task is to track the game by scent from particular distance to the constructed game's lair, enter the animal's tunnel and then "work". Work is defined as digging, barking, growling, lunging, biting at the quarry, or any other action which, in the opinion of the Judge, indicates the dogs interest in the quarry. It is important to mention that since rodent is in cage, dog can see it, but it can not touch it or harm it. Tunnel height and width are 23x23cm, while length depends on dog's working ability level. In Earthdog may participate all smaller terrier breeds and dachshunds. Since this is a web site about Bull Terrier it implies that Bullies may participate, but naturally only Miniature Bull Terrier.

There are 4 levels of dog's working ability:     - Introduction to Quarry - where for dog to pass the test is given 2 minutes from the time it first enters the earth to begin working the quarry in a tunnel 3 meters long with one 90 degree turn. When dog engage the quarry it must work continuously for 30 seconds. If the dog is not reacting to the presence of the quarry, the Judge may attempt to interest the dog with no penalty to the dog.       - Junior (JE) - with given 30 seconds to begin working with quarry in a tunnel 9 meters long with three 90 degree turns. Dog must work continuously for 60 seconds. The Judge shall make no attempt to encourage the dog to work.

    - Senior (SE) - with the tunnel also 9 meters long with three 90 degree turns, but with false entrance and false lair. Dog has 90 seconds to find quarry. Once the dog has reached the quarry the Judge shall allow the dog 15 seconds to begin working. Once the dog has started to work, it must work the quarry for 90 seconds continuously. The Judge shall make no attempt to encourage the dog to work. The Judge shall then instruct the handler to recall the dog. The handler may go to the entrance of the den to call the dog or may use a whistle. Dogs which are retrieved by the handler within 90 seconds from the recall shall pass the test.
     - Master (ME) - tunnel is of exact dimensions as in preceding two tests. In this, most demanding test, dogs (not familiar to each other) are worked two at a time. During the test, the dogs are expected to work together without interference or aggression. Dogs may investigate the false den, but dogs barking in or working in the false den cannot qualify. The first dog to indicate the real entrance enters the lair, must reach the quarry within 90 seconds and should begin work within 15 seconds. The dog must work the quarry steadily for 90 seconds. The second dog to indicate the entrance shall be staked approximately 10 feet from the main entrance, shall be collared with a flat collar and the handler may attach a lead to the collar. The honoring dog must show interest and may be occasionally vocal, but shall not bark continuously. At the completion of the working portion, the first dog shall assume the honoring position, while the second working the quarry.

  My opinion is that every person who owns a terrier should take his dog to earthdog trial if he has the chance, because this way he can check instinct and "blood" of his terrier and provide to himself and his dog great pleasure.