Editorial: Stacked Shoes, Studies & Jumping to Conclusions

Candace Wade outlines a recent study on the effects of stacked shoes and chains in Tennessee Walking Horses and argues why the study’s conclusion may be misleading out of context.

A Tennessee Walking Horse in stacks, often used in the performance ring. Public domain.

I was skeptical right at the title of the study — Effects of stacked wedge pads and chains applied to the forefeet of Tennessee Walking Horses for a five day period on behavior and biochemical indicators of pain, stress and inflammation. No “big lick” Tennessee Walking Horse (TWH) is fitted with stacked shoes for only five days. I waded through the 12 pages of this mind-numbingly technical document. My brief outline of what I read and why I feel this study is unrelated to the welfare of TWH follows.

Who and Why This Study

The study comes out of the University of Tennessee College of Veterinary Medicine for publication in the American Journal of Veterinary Research. The team of researchers comes from several universities. (The schools that have staff involved in the study are listed at the end of this article.*) Under “Objective,” the goal reads: “To determine the effects of stacked wedge pads and chains applied to the forefeet of TWH on behavioral and biochemical indicators of pain, stress and inflammation.”

This study as performed cannot accomplish the objective. My reasons are organized into two categories: How the horses were tested, and the study/document itself.

The Method of Testing the Horses

Let me stipulate that studies (of any kind) have analytic models used to represent the data and that the models must reflect what actually happens outside the “test lab.”

Age: The median age of the 10 horses in the stacked-shoe/chain portion of the study was approximately 10 years old. (The range was from five to 15 years old.) Show horses can be in training at 16 to 18 months and shown in full devices, with an adult rider, at two years old.

Pre-study physical condition: The study horses had lived “like horses” outside and moving freely. The long term free movement builds muscle that stall confinement of show horses does not build. I did not read that any of the test horses had ever been shod in stacked shoes prior to the test.

The number of days tested: The study horses were tested in stacked shoes and chains for five days. (Show horses can be in these devices for years.)

Minutes of test activity per test day: The study horses were exercised in shoes and chains for 20 minutes a day. This is the average time in daily training and/or the show arena, but actual show horses likely remain in the stacked shoes much longer than five days.

The speed of test gait: Flat-walk speed of the hot walker used to exercise the horses. The horses were not tested at the running walk or canter — the gaits performed in the show arena and in training.

Other deficiencies: At no time did test horses carry riders. The heavier and multiple chains used in training were not used. The “specific” accelerometer cited for gathering behavioral data is used for acquiring data on dairy cows and hasn’t been validated for use on horses.

These differences (and others) are noted with care in the study document. One can consider these as caveats to the results. The results noted that no significant differences were observed in the various chemical responses measured between the 10 keg-shod test horses and the 10 stacked-shoe and chain test horses.

The Document

I noted repeated non-scientific use of the “soft connotation” term “bracelet” — I have heard the term “bracelet” repeated by supporters of the big lick training methods. The “bracelets” I have seen on horses and at shows are large-link chains.

How was the study protocol created? Who created/devised the testing method/protocol? Who requested the study? How much money was granted for the study? I asked these questions of one of the DVMs on the study. I was told answers would be provided. I had not received answers as this story went to press.

Who funded the study? It seems to have been funded by a UT fund called TN Equine Veterinary Research Organization. I have been unable to find the usual legal non-profit status credentials for TEVRO.

The study document is peppered with caveats like “… not completely similar…” and  “… results should not be generalized to the long-term use of these devices in horses performing the running walk…” “… effects of these devices should be examined when horses are exercised with a rider at a speed and duration typical of those demanded while hose are in training.”

My Concern: The Conclusion

I am concerned that the conclusion “this study evoked no acute stress” will be the story. My concern is that this study will be cited as proof that the use of stacks and chains don’t impair the physical and “behavioral” health of big lick TWHs. I am concerned that this study will be used to influence — mislead? — legislators to continue to stall a vote on the PAST Act. My concern is for the improvement of the welfare of gaited show horses.

*Representatives from the following schools participated in the study: The Departments of Large Animal clinical Sciences and Animal Science College of Veterinary Medicine, University of Tennessee, Knoxville, TN and the Veterinary Diagnostic Laboratory, College of Veterinary Medicine, Iowa State University, Ames, IA and Department of Anatomy and Physiology College of Veterinary Medicine Kansas State University, Manhattan, KS.