Friday, October 28, 2011

Another Way Of Looking At Early Take-Off Syndrome

Another Way Of Looking At Early Take-Off Syndrome
by Chris Ott
The phrase Early Take-Off Syndrome was coined to describe the behavior of taking off in an inappropriately early spot when jumping, usually in relation to agility training and competition.  It appears that, for whatever reason, the dog is not measuring correctly and therefore miscalculates position.  There are a number of theories as to why this happens, but nothing definite is known yet.  There are some breeds, and some lines within certain breeds, that seem to manifest this issue frequently, but it is also seen in individuals of a wide variety of breeds.  It is tempting to assume that this issue is genetic in nature, and further research may indeed find that it is, however it is equally important to realize that at this time there is no definite proof that the problem is genetic, nor is anyone entirely clear on what is actually causing these dogs to manifest this particular jumping style.
There is a common is expression in scientific research, correlation does not imply causation, that is important to bear in mind as we move forward in research on the topic of dogs taking off too early when jumping.  As tempting as it is to point to a specific breed, or a specific line within a breed, or a specific sire or dam within a line as the carrier of the problem, our dogs are raised with far too many variables to make any such clear cut assumptions.  While it is important for people who are searching for dogs as agility prospects to eventually have an understanding of what causes this issue, it is equally important not to present guesses, no matter how educated, as fact, and to proceed carefully as we learn more about the possible causes.  It is also entirely plausible that, while the issue manifests the same symptoms in different breeds, the cause might be different in different breeds, or even in different dogs of the same breed.  
Chris Zink, D.V.M., Ph.D., is a consultant on canine sports medicine, evaluating canine structure and locomotion, with an expertise in re-training problem jumpers.  When asked whether she felt ETS was an actual syndrome or a variety of unrelated jumping issues lumped together, Dr. Zink had this to say:
“I hesitate to call it a syndrome, however, since that implies physical or psychological illness. (Definition of 'syndrome': A group of symptoms that collectively indicate or characterize a disease, psychological disorder, or other abnormal condition.) I truly believe that taking off too early often is exacerbated by vision issues or physical structure, but that at its core it represents a basic misunderstanding on the part of the dog of how to approach the complex job of jumping, particularly jumping in agility, where speed is desirable and complexity is high.”
As published by M.W. Fox in Electroenceophalography and Clinical Neurophysiology, 24(3), 1968, pp 213-226, in a study of the development of evoked responses in restrained but unanesthetized dogs of various ages using chronically implanted electrodes in the visual and auditory cortex,
Development of visual and auditory evoked responses was rapid during the 1st 3 wk. of life, attaining relatively mature characteristics by 4-5 wk. Neuronal development in both complexity by 4-5 wk. the most rapid development occurring during the 1st 3 wk. in both the deeper and more superficial cell layers. Subsequent developmental changes were more gradual, and contrasted the rapid development of all parameters studied during the period from birth to 3 wk. 
Early visual stimulation, or the lack thereof, appears to affect the development of vision.  Drs. David Hubel and Torsten Wiesel, recipients of the 1981 Nobel Prize in Physiology or Medicine for their discoveries concerning information processing in the visual system clearly demonstrated the lack of early visual stimulation can permanently affect vision, and this research became the basis for programs of early visual stimulation for infants with possible visual impairment.  While again, correlation does not prove causation, puppies from the same litter, in addition to having the same genetic background, also share the same early visual stimulation experiences, so the fact that puppies from the same litter manifest the same visual problem does not automatically indicate a genetic factor.  It is entirely possible that modifying early puppy visual stimulation might cause great improvement in the dogs’ later ability to gauge jump distances correctly.  The method in which the dogs are trained to jump also needs to be taken into consideration as it is not uncommon for dogs from the same litter to be trained in the same classes or with the same trainer.  It is perhaps the case that certain types of training, or certain types of early visual stimulation, are necessary for specific dogs while not being as needed for other dogs.  
Anecdotally, I have found that many dogs who exhibit this form of jumping issue also struggle with impulse control, confidence and/or have other behavioral issues.  Whether this is a cause or an effect, or purely coincidental, we do not know, but it is another factor that perhaps needs to be taken into account when looking at possible causes.
We asked Dr. Zink whether she felt that it was possible that ETS was caused or exacerbated by certain training methods and she responded that,
“I do think that this is the case. And I have only come to this belief recently. With my own dog, once she was mature and I lost a little weight, I started to push her for speed. Certainly we both were capable of moving faster over the ground. But that is when she started to take off earlier. I believe that this was because she was trying harder, running faster and as a result failing to realize that she still had to collect her strides before the jump. The harder she ran the sooner she took off. By retraining her to collect her stride, her jumping problem resolved. But it took about 3 months, and still requires ongoing training to remind her to collect. 
I also wonder whether this problem occurs more with dogs that are pushed for speed at a young age. There is a belief by some trainers that you should not ever have the dog do agility slowly or the dog will never achieve its full speed. Others believe that you should let the dog learn at its own pace, then allow them to ramp up their speed when they become confident. I suspect that dogs in the first group are more likely to have problems with taking off too early.“
There is very little research available on depth perception in dogs.  One paper,  Evidence for averaging of distance from landmarks in the domestic dog. Fiset, Sylvain; Behavioural Processes, Vol 81(3), Jul, 2009. pp. 429-438, looks at several studies in landmark use and finds that studies have shown 
“that animals locate spatial positions by predominantly using perpendicular distance from extended surfaces over distance from individual landmarks. In the current study, I investigated whether the domestic dog encodes perpendicular distance from surfaces and whether they estimate distances from multiple cues.” 
And it is known that dogs who are blind in one eye continue to have functional depth perception, despite no longer having stereoscopic vision.  Indeed, there are several one eyed dogs competing quite successfully in agility.  This is another indication that there are several factors at work in functional depth perception.
Most importantly, dogs who exhibit this form of jumping problem, while not ideally suited for careers in agility competition, are not actually handicapped.  Dog breeds were designed for specific tasks, and in breeding dogs perhaps the most important question is whether the dog is sound and healthy and can excel in performing the task for which the breed was designed.  Very few breeds have jobs that require them to jump in the way that agility competition requires.  Norfolk Terriers, for example, a breed with a very high incidence of dogs who take off inappropriately early when jumping, are bred to hunt varmint, often in burrows and other areas entirely void of light.  They, in effect, hunt blind.  Their ability to correctly gauge the take off spot for a jump is not in any way required for them to live long, productive, healthy lives.  Culling dogs from the gene pool because they manifest this issue would be a disservice to the breed as it would further shrink a very small gene pool and make it harder to breed dogs with low inbreeding coefficients.  Border Collies who manifest this issue also will not suffer any impairment in their ability to perform as herding dogs.  
People who are breeding dogs of any breed specifically to produce agility prospects without concern for the actual original purpose of the breed, must, of course, take into consideration, among many other considerations, whether the dogs manifest this particular jumping issue.  If one is aware that a dog seems to have produced a number of dogs who exhibit difficulty correctly measuring jumping distance and take off too soon, then one has to consider all factors involved to make as educated a decision as possible about whether or not to breed to the animal, and what modifications, if any, they might choose to make when raising and training the resulting puppies if they do choose to breed the dog.  For many breeders it might be most comfortable to abstain from breeding to these dogs until more is known about what might cause dogs to manifest this jumping issue, but neutering dogs who otherwise are excellent additions to the gene pool (dogs structurally and mentally sound dogs with all health and genetic clearances for their breed who have excelled in whatever form of competition they partake in, for example) might be taking it too far.  Rather than cull these dogs from the gene pool entirely, perhaps a more cautious course of action would be to withhold breeding to them at this time, perhaps collecting semen for possible use at a later date when more is known about factors causing the problem.
When Dr. Zink was asked if a dog is otherwise healthy, has passed all health clearances for the breed and is able to excel at the task for which the breed was originally created (herding for BC, ratting for Nors, etc.) do you think that evidence of ETS in a dog is reason enough to cull a dog from the gene pool?  She responded:
“Absolutely not. And I am shocked to hear that people have been spaying/neutering dogs that have this problem, believing it to be genetic. I hope that is just a rumor.”
Research is currently underway to try to tease out what this syndrome actually is and whether there is a single factor causing the issue.  I feel strongly that waiting to make any major decisions about culling dogs from the gene pool until after the research is complete might be the most reasonable course of action.
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