Grayson-Jockey Club Research Foundation’s board of directors has approved a 2019 budget of $1,338,858 to fund eight new projects, nine continuing projects and three career development awards. This is the fifth consecutive year that more than $1 million has been approved.
“We thank our generous donors who recognize the value of veterinary research for enhancing equine health and wellness,” says Jamie Haydon, president of the foundation, in a recent e-newsletter. “From studying a racehorse’s stride to predict injury to testing an intrauterine antibiotic treatment, we are excited to see the results of these studies and how they may help horses of all breeds in the future.”
Seven projects, in particular, are of interest to footcare professionals, with objectives including development of better imaging through computed tomography (CT), positron emission tomography (PET), radiography and 3D imaging, as well as the prevention of fetlock injuries.
As per the foundation’s established procedure, the funded projects were considered the best science by the foundation’s 32-person Research Advisory Committee (RAC). That committee comprises university researchers and veterinarians from various practices.
Training Programs for Prevention of Fetlock Injury
This study, to be conducted by Sue Stover of the University of California Davis over a course of 2 years, aims to predict proximal sesamoid bone (PSB) fractures in racehorses using a calibrated computational model that incorporates training programs, track surface properties and bone’s reparative processes.
The PSB, located in the fetlock joint, accounts for 50% to 60% of all racing and training fractures. Due to the location of the PSB, there is no reliable way for veterinarians to classify an animal as at risk for fracture before an event. It is also known that fractures do not occur as an isolated event, but as an accumulation of bone damage over a racehorse’s career.
The goal of this project is to enhance a finite-element computational model of Thoroughbred (TB) PSBs to predict risk based on the training history of the racehorse. The use of training history, race surface information and a mathematical model of bone’s innate repair processes will be used to predict damage in PSBs.
The project consists of three main steps or aims. The first is to calibrate the existing finite element model that uses training and race history as input factors to predict PSB damage, healing and porosity. Data collected from 20 case-and-control TB racehorses with PSB porosity and microdamage data will be included. The second aim is to test the model’s ability to predict PSB fracture using existing exercise history data from 392 TB racehorses. Then, using the results, necessary modifications will be made to the model for the general racehorse population. The last aim is to determine what constitutes as a “high fracture-risk” exercise program by determining how the training regimen and exercise surface can contribute to the predicted PSB fracture-risk.
Robotic CT for Assessing Bone Morphology
Kyla Ortev of the University of Pennsylvania will be conducting the study on the prevention of devastating injuries in TB racehorses through screening fetlock joints using standing robotic CT and biomarker analysis. The grant duration is 2 years.
As bone and joints become worn, the body adapts to stress through maladaptive stress remodeling. However, if the repetitive stress cycle doesn’t cease, microfractures can lead to stress fractures or even collapse of the joint surface, which is irreversible. Diagnosis early on is crucial, however extremely challenging.
Plain radiographs are not sensitive enough to identify subtle bone changes that might suggest microdamage. CT is the best for evaluating bone, yet requires the use of anesthesia. MRI faces the same issue of putting the horse under, and standing MRI scans are time-consuming. New technology has emerged, allowing a CT scan to be performed in the standing, sedated horse in less than a minute. Robotic arms traverse 360º around a particular part of the limb, taking images that are later transposed into advanced motion correction and reconstruction software.
Research has already gone underway of collecting images of first-year racehorses, as well as blood samples to look for blood markers affected by training. Specific blood markers include levels of osteocalcin, which marks bone growth; and CTX-I, which is a marker of bone breakdown and markers of inflammation. Where collection of robotic CT imaging is the first aim of this study, collecting blood samples is the second.
Racehorse Stride Characteristics: Injury and Performance
University of Melbourne’s Chris Whitton will be studying and identifying changes in stride characteristics of racehorses over time to isolate parameters in order to develop an early indicator of injury or in injury development. The grant duration is 1 year.
There are many risks associated with racehorse injuries, including management, environmental and horse-level risks. These could include race type, distance, surface, age, prior injury and others. Changes in normal galloping stride patterns are possible to identify, and in lame horses and horses restrained by a rider both demonstrate higher limb velocity than overall horse velocity. This is due to a decrease in stride length and stride time. The uncertainty lies in which characteristics are most important and how they interact with the fatigue of the bone.
The proposed research will take advantage of stride characteristics of racehorses collected in a database over 5 years (2011 to 2016) using StrideMASTER, a company that uses a GPS tracking system and precision sensors on race days in Tasmania, Australia. The goal is identifying key stride characteristics that might be associated with an increased risk of injury, fatality or poor performance.
The specific aims of this study are first, to determine the different strides for different styles of racing and variations within these groups of racehorses and second, to identify key racing styles and changes in stride characteristics that result in injury.
Standing PET of the Racehorse Fetlock
In the second year of his 2-year grant, Mathieu Spriet of the University of California, Davis will continue studying the validation of a PET technology for early detection of fetlock lesions in standing horses to prevent catastrophic breakdowns in racehorses.
PET scans employ the use of a small amount of injected radioactive tracer, which concentrates in abnormal areas of the bone. This leads to the identification of bone injuries with the 3D information in high-resolution, which provides precise localization of the abnormalities.
The current main limitation of PET scans is the use of anesthesia. To avoid the risks associated, a standing PET scan has been introduced, requiring only a sedative or tranquilizer. The scanner features a circular design that can be positioned around the limb with a ring of detectors that opens freely for optimal positioning.
The first part of the study was to validate the new PET scanner by comparing its images to the old PET scanner images. Part two features a clinical trial comparing findings from bone scan images and standing PET scan images of racehorses at Santa Anita Racetrack.
TB Sales Radiology-Ultrasonography Study
C. Wayne McIlwraith of Colorado State University will continue studying the improvement of the industry’s understanding of the significance of sesamoiditis, ultrasonic suspensory branch changes and stifle lucencies in sales yearlings and 2-year-olds. This is the second year of a 2-year grant.
A controversy within the TB industry includes the varying opinions in veterinary interpretation of certain findings on pre-sale radiographs. The uncertainty of the imaging can negatively affect the sale of young horses, frustrating breeders, consignors, buyer and veterinarians. More frequently, suspensory branch ultrasonography is becoming more frequent in sales yearlings. Researchers will evaluate the radiograph information of 2,975 yearlings of which permission was granted from the 2016 Keeneland September Sale. The yearlings will be compared with 2-year-old sales radiographs of 473 of the same horses.
The goal of this study is to provide the industry with a better understanding of sesamoiditis and stifle lucencies. Information gained from this large-scale scientific research and the information pre-sale radiographs should allow the seller and prospective buyers to make an informed, confident decision in collaboration with veterinarians. Boosting industry-wide confidence in the sales repository system and the veterinarian’s role in the trade, management and care of racehorses is another key goal.
AMPK Agonists and Insulin Dysregulation in Horses
Teresa Burns of the Ohio State University will continue work on her 2-year grant project investigating the treatment of equine metabolic syndrome (EMS) by assessing the efficacy of two drugs, metformin and acetylsalicylic acid (aspirin), in the treatment of equine insulin dysregulation.
Currently, treatment for EMS includes reducing abnormalities in insulin and glucose responses to food by reducing the amount of sugar and starch in the diet. Medications that activate a key enzyme that regulates metabolism in virtually all cells in the body promote normal blood sugar levels, burn fat and improve insulin in treated humans. Since EMS shows similar metabolic problems in horses, the enzyme activation would be an ideal method of treatment. However, it is unknown whether the medications will active the same enzyme in horses.
Metformin hydrochloride actives the enzyme through an oral dose, and although it is already given to horses, not many studies have been conducted on its use and efficacy. Metformin is not absorbed from the GI tract in horses as well as in humans. Some investigators suggest that the medicine acts internally, blocking sugar absorption within the intestine.
Recently, aspirin has also been shown to activate the key enzyme in humans. Aspirin is well-absorbed in the intestines of horses. The plan of the study is to induce temporary insulin and glucose abnormalities in 14 adult horses using dexamethasone. After 7 days, seven horses will be treated with metformin and the remaining with aspirin for 6 days.
Blood samples, liver biopsy and skeletal muscle biopsy samples will be collected at various points of the study, including baseline, following induction of glucose and insulin dysregulation, following metformin or aspirin theory and following combination therapy. It is hypothesized that the two drugs will improve insulin and glucose dynamics in horses with insulin dysregulation.
Development of Limited View 3D Imaging
Colorado State University’s Chris Kawcak will continue working in the second year of the 2-year grant on the development of a point-of-care, 3D imaging technique that can be used to better characterize and prevent injuries in racehorses.
The goal of this study is to create an inexpensive, easy-to-use and easy detection device for finding subtle changes within the legs of horses to prevent injuries. Specifically, the device will be designed for the equine distal limb, including a minimal number of radiographs to create the 3D image of the leg.
First, the investigators propose to use computer simulation techniques to design the device. Once the computer simulation is finalized, the model will be validated by imaging the fetlock joints and comparing the results to the model. A board-certified radiologist will then evaluate the images blindly. A prototype will be created then and tested before being brought to the equine market in collaboration with Colorado State University.
The 3D images can provide more information about the health of the horse’s legs using a minimal number of x-ray projections. This technique can also be obtained through a limited number of radiographic views. The goal of this study is in its results that will lay the groundwork for software and hardware design of this device.
Since 1983, the Grayson-Jockey Club Research Foundation has funded more than $27.5 million to underwrite 366 projects at 44 universities.