Reducing Fetlock Fractures Through the Use of Standing MRIs

By: Zachary Atwell

As the thoroughbreds raced to the top of the final stretch in the 134th Kentucky Derby, Eight Belles began to make her move. Galloping toward the inside rail, the lone filly pulled away to second place with only one furlong left. Giving a heroic effort until the very end, she finished the race behind only Big Brown, the overwhelming favorite, who crossed the wire 4 ¾ lengths ahead of her.[i] In a way, the second-place finish was a victory, as Eight Belles had become only the second filly to place in the Kentucky Derby.[ii] However, this immense triumph was tragically short-lived for the thoroughbred. Only moments after completion of the race, and with the crowd still roaring, Eight Belles gave way on the track with two broken bones.[iii] With no way to save her, on-call veterinarians were forced to euthanize the filly.[iv]

An autopsy of the body revealed that she had “suffered fractures in the sesamoid and metacarpal condyle bones of the fetlock, or ankle joint.”[v] Eight Belle’s untimely death and the release of the autopsy report sparked controversy regarding the thoroughbred racing industry, as well as the horse industry as a whole.[vi] Ed Whitfield, then-U.S. Representative of Kentucky’s 1st congressional district, criticized thoroughbred racing and voiced his concern that thoroughbred horses are seen as profit.[vii] Whitfield’s remarks reflected a long-held belief, which later became the basis for his push for federal legislation on racehorse medication.[viii] Such legislation may prove useful in addressing some of the problems leading to horse injuries and deaths. However, prevention starts with thoroughbred breeders, trainers, and veterinarians.

Fetlock fractures, like the ones suffered by Eight Belles, are the leading cause of euthanasia in thoroughbreds globally.[ix] A horse’s legs are subjected to a lot of stress and tension during training and racing.[x] Should a pre-existing disease or “bone change” be present, condyles in the foot may then fracture under such stress.[xi] If veterinarians were able to detect such changes before a race, they could then take steps to prevent a fetlock fracture from occurring.[xii] Based on recent research, magnetic resonance imaging (MRI) scans may prove helpful in alerting veterinarians to these indicators.[xiii] Between 2011 and 2013, John Peloso, DVM, a surgeon at the Equine Medical Center of Ocala, Florida, took MRI scans of eighteen horses that suffered deadly fetlock fractures while racing.[xiv] Of those eighteen, 67 percent had a 50 percent increase in condyle bone density, which is a reaction to significant stress.[xv] These results demonstrate the potential promise of using MRI scans.

Credit: Doug Herthel; Source:

Credit: Doug Herthel; Source:

Although MRI scans may prove to be a useful tool in reducing the occurrence of fractures, they are not without their faults. Traditional MRI scans for horses require the animal to lay on its side, which in turn requires the use of anesthesia.[xvi] This can prove risky, as use of general anesthesia can lead to death in nearly 1 in 100 horses.[xvii] While that statistic is not high, repeated MRI scans only increase the likelihood of an anesthesia-related death.

A safer and more practical alternative to the traditional MRI machine is Hallmarq’s “Standing MRI.”[xviii] The machine can provide high-quality MRI scans while a sedated horse is standing, thereby eliminating the need for anesthesia.[xix] Since its introduction, the Hallmarq machine has revolutionized veterinary diagnostic imaging and has proven successful worldwide. Recently, the 100th MRI unit was installed at Pferdeklinik Dalchenhof in Brittnau, Switzerland.[xx]

To reduce fetlock fractures and protect the quality of life for horses and the reputation of the horse industry, breeders, owners, and veterinarians should use, and encourage the use of, standing MRI machines.

[i] Associated Press, Runner-up Eight Belles breaks front ankles, euthanized on track, ESPN (May 3, 2008),


[ii] Ray Wallin, Will We Ever See Another Filly in the Kentucky Derby?, US Racing (April 2, 2019),


[iii] Runner-up, supra note i.


[iv] JR Minkel, Horse Racing’s Cripple Crown?: Industry Works to Prevent Fatal Injuries, Scientific American (May 16, 2008),


[v] Id.


[vi] CBS/AP, Eight Belles’ Death Sparks Controversy, CBS News (May 5, 2008),

[vii] Janet Patton, Kentucky’s Whitfield renews call for federal horse racing legislation, Herald Leader (March 28, 2012),

[viii] Id.


[ix] Alexandra Beckstett, MRI to Predict Catastrophic Fetlock Fractures in Racehorses, The Horse (May 5, 2015),


[x] Id.


[xi] Id.


[xii] Id.


[xiii] Id.


[xiv] Id.


[xv] Id.


[xvi] Hallmarq Standing Equine MRI Machine Reduces Risk to Horses, The Horse (July 22, 2013),


[xvii] Id.


[xviii] Hallmarq Installs 100th Global Equine Standing MRI; Renews Focus on North American Equine Market, The Horse (August 29, 2019),


[xix] Id.


[xx] Id.