Because of the small size of a Dandie Dinmont Terrier, they are quite capable of being successful in underground earthdog testing. The tests are conducted as non-competitive trials in order to assess the hunting ability of an individual dog during the performance of an underground hunting expedition. Owners don't have to be concerned with their dogs being in danger as the encounters are controlled.
In the AKC testing environment, the program begins with your dog being shown the basics of den work and quarry. He then progresses gradually until he reaches the point of being able to demonstrate a willingness to perform all of the tasks that are required up to and including seeking and working the quarry in an underground environment. The use of the term "working" means that your dog will use his hunting skills in order to "capture" the quarry. This may involve barking, growling, chasing, and any other means that he has at his disposal.
The AKC Earthdog Program has several levels of achievement your dog must reach in order to progress to the next level. The first level is Introduction to Quarry for dogs that are new to earthdog trails. Since each dog has its own level of drive when it comes to prey, this area is designed to provide your dog with an introduction to what "going to ground" means and how to follow a scent on the trail and sniff it out. This step involves a 10-foot tunnel with a rat in a cage at the end. The dog receives encouragement from the handler to "work" the quarry until he finds it.
The first competitive level is that of a Junior Earthdog. In this trial the tunnel is 30 feet long with a minimum of three turns on a right-angle. The dog has a maximum of 30 seconds to follow through the tunnel in order to reach the quarry. Another requirement is for the dog to work the quarry for 60 seconds before allowing the handler to remove it. He must perform the test twice with different judges in order to receive a certificate as a Junior Earthdog. The final two levels are the Senior Earthdog and Master Earthdog.
Not all dog breeds are qualified to participate in the Earthdog trials. They are limited to terriers and the Dachshund because of their small size and ability to maneuver small places. In addition, they are the smaller of the hunting dogs and are reliable in their quest to reach prey both in the trials and when assisting their owners in their quest for prey. Though the training itself is non-competitive, your dog can certainly compete in order to be recognized as a Junior, Senior, or Master Earthdog. Even if you aren't going to use your Dandie as a hunter, you can certainly give him an opportunity to compete in the trails and earn a certificate. It gives him an opportunity to compete for something while providing good exercise as he runs through the tunnel to reach the quarry.