This can be challenging especially if you have a dog that deals with anxiety. However, when they actually learn it the trick becomes a quick favorite. Before you start, make sure you have a short, stable, and high quality tunnel.
How to teach them? The first step is to get them comfortable with the tunnel by placing treats at the mouth of the tunnel. Place the treats further and further inside and praise the dog for getting them. Finally, stand on the other end of the tunnel with the treat and lure the dog to it. With a shot tunnel to begin with this should be easy.