Clean Run - November 2017 - 33

lem, like popping up or huge overjumping at a young age, and some dogs that
seemed not to jump in what we refer to
as extension. Some dogs' jumping style
was to tuck their rear legs under them
rather than extending their rear legs
out in a nice arc. We have since learned
that this can be a defensive response
by the dogs upon realizing they may
hit the bar with their stifle or underside
on descent; at times they tuck up their
rear ends tightly to avoid a possible collision. But as with many ETO behaviors,
it doesn't apply across the board. Many
ETO dogs do not tuck up on jumps and
often choose to jump in extension, and
some great jumpers tuck their rear legs
sometimes, likely due to their structure.
As an instructor, I did not know how to
help these dogs. And the problems were
starting to show up in a variety of breeds
and in dogs that were extremely successful competitive agility dogs. Over
the years there have been at least five
dogs with somewhat pronounced ETOs
on the AKC/USA World Team. These
were fast and athletic dogs with great

November 17 | Clean Run

trainers and handlers. Why couldn't we
fix the dogs' ineffective and problematic
jumping style? And, just as importantly,
we all wanted a real diagnosis so we
would be able to repair these dogs, or
at least prevent the problem via some
medical answer.
In years of watching how ETOs developed in these dogs, we started to notice
that dogs coming from certain lines and
breeders had more tendency to have
ETOs. One of my students started being able to identify marker dogs in her
breed for producing dogs with ETOs.
Eventually it became easy to pinpoint
some of the breeders and some of their
dogs that produced dogs with ETOs.
The vision issues which cause ETOs
can be hereditary, just like myopia is
hereditary in people, but they can also
be congenital. As early as 2009 I began
referring handlers with ETO dogs to veterinary ophthalmologists for examination and we discovered that some of the
causes were diagnosable diseases like
vitreous degeneration. I began reading
all the articles I could find on dog vision

and realized there is already scientific
evidence that suggests vision deficits
create problems for dogs doing the jobs
they were bred to do, like field dogs and
guide dogs.

A Summary of Studies
Following is a short description of some
of the most relevant study abstracts that
led me to my final theories on vision abnormalities in dogs and how our agility
dogs' jumping is affected. I encourage
you to delve into some of these articles
to educate yourself and also gain a further understanding of how vision in
our dogs affects their lives. Complete
information on each abstract as well as
a website link for getting a copy of the
article is included in the references at
the end of the article.
Dr. Chris Murphy from UC Davis did a
study on field dogs where he artificially
created myopia by using different levels of cloudy contact lenses.1 From the
abstract published in 2010: "Even mild
myopic defocusing had a significant
negative impact on both the subjective

http://www.letsgodesign.net

Table of Contents for the Digital Edition of Clean Run - November 2017