I found an article on Linda Mecklenburg's website Awesome Paws that talks about what she refers to as Early Takeoff Syndrome. What got my attention is that she thinks it is a problem with depth perception which is something I have always said I thought was the problem with Ceilidh. Ceilidh jumps the tire, doubles, and spreads usually without too much hesitation but with single jumps especially with the ones with small metal uprights, she hesitates or stutter steps. At 16", her Regular jump height, she would go around and then back jump as if she had to figure out exactly where the bar was. She never did that with winged jumps, doubles, spreads, or tires which led me to believe that those types of jumps have more cues about the depth of the jump. Ceilidh also doesn't like toys (or anything for that matter) thrown in her direction. She also doesn't like it when I take a jacket off over her head. And in poor light, she has trouble jumping off a bed or going down stairs when she is not familiar with them. All of these things indicate she has some problem with her eyes so I had her eyes tested to ensure that PRA was not present. There was no indication of retinal deterioration so I am left believing that it is, in fact, a depth perception problem.
Below is an excerpt from the article on Linda Mecklenburg's web site, there is also a short video clip on the web site of a border collie displaying the hesitation or stuttering just before the jump.
Early Takeoff Syndrome
"Early takeoff syndrome describes a jumping problem seen in some agility dogs where they do just that: they take off too early for the jumps. The syndrome ranges from a subtle hitch on the dog’s final stride to severe stuttering. The dog typically inappropriately chooses to shorten its last stride before takeoff. This results in the highest point of the dog’s jumping arc peaking before the bar and the dog is on the descent phase of the arc by the time it actually clears the hurdle. This should not be confused with simply a long takeoff distance which, if balanced with an equally long landing distance, simply means the dog is jumping with a flat jumping trajectory.
Early presentation of this problem can be very subtle and takes close observation. The faster the dog is, the more likely it is to be apparent because the shortening of the last stride results in a more noticeable change in the dog’s speed. Obstacles with components that extend forward of the jumping element, such as the tire and triple, may cause more problems. Many affected dogs will also shorten their last stride on the approach to the A-frame and/or table. For some dogs, the problem will increase with changes in the lighting on the course.
If a dog begins to show changes in his jumping habits, the very first step is to rule out any physical problems that might account for it. With ETS, the dogs are physically sound. There seem to be certain breeds of dog and certain lines within those breeds that may be affected. This includes some of the breeds that are known for jumping problems but Shelties and Border Collies can also be affected. I do not know the cause of this problem. I do not believe it is a training issue although as I said a lack of confidence makes the problem worse. It appears to be a problem with vision and/or the dog’s perception of where the bar is in space. Many dogs with this problem have had normal cerf exams and some have even been tested for near and farsightedness (with variable results). To my knowledge, there is no test for depth perception in dogs at this time. I’m hoping with increased awareness and demand from agility competitors perhaps that will change, so that a definitive cause for this syndrome can be identified and perhaps steps taken toward treatment and prevention. "