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The University of California Davis (UC Davis) permanent positron emission tomography (PET) scanner is officially in use at Golden Gate Fields racetrack in Berkeley, Calif., Providing imaging at the molecular level to monitor the racehorse health and guide training and medical care. The CT scanner (LONGMILE Veterinary Imaging’s MILEPET) allows imaging of a lightly sedated horse’s leg, eliminating the time, cost and health risks associated with general anesthesia. In use at UC Davis Veterinary Hospital since March, the instrument has been transported by a team of UC Davis vets and technicians to Golden Gate Fields Equine Hospital once a week for the past month.

Mathieu Spriet, DVM, MS, Dipl. ACVR, ECVDI (LADIS), the equine radiologist who pioneered equine PET, is very excited about this new development. “Using the PET scanner at Golden Gate Fields brings multiple benefits,” said Spriet. “First, it provides horse racing in Northern California with the same technology that has helped improve the health and safety of racehorses in Southern California. Second, it demonstrates that the equine PET scanner can be transported and shared efficiently between multiple sites, reducing costs and increasing uptime. And finally, it opens the door to more research opportunities with the realization of multicenter studies. “

This achievement was supported by the UC Davis Center for Equine Health and the Stronach Group, owners of Golden Gate Fields. Both parties have been intimately involved in the development of equine PET. The Center for Equine Health was behind the first equine PET scan performed at Davis in 2015 and has since supported the development of the modality by funding several research projects as well as a clinical program. The Stronach Group has played a key role over the past two years in providing partial support for the development of the first scanner to allow imaging of standing horses to prevent catastrophic breakdowns in racehorses.

The original MILEPET, owned by the Southern California Equine Foundation with support from the Stronach Group, has been in use at Santa Anita Park since December 2019. In a year and a half, more than 200 horses have been imaged with the scanner, multiple on multiple occasions. Research projects supported by the Grayson Jockey Club and the Dolly Green Research Foundations have helped characterize the value of PET in racehorses. The PET scanner is ideal for imaging the fetlock (the horse’s ankle), which is the most common site of catastrophic injuries in racehorses. The first research study in Santa Anita showed that PET scans were far superior to bone scans, another imaging technique used at racetracks, to identify injuries in the sesamoid bones (the small bones at the back ankle). Two subsequent studies demonstrated the value of PET for monitoring injury during healing and joint health when horses return to training.

The use of PET in Santa Anita, coupled with the use of MRI and changes in medication rules, is one of the many factors that led to a marked decrease in the number of deaths between 2019 and 2020. Building on this success, the Stronach Group was eager to bring the same technology to Golden Gate Fields. The proximity to UC Davis offered a unique opportunity to use the scanner at both sites. He is currently available at UC Davis Veterinary Hospital four days a week and at Golden Gate Fields one day a week. The scanner’s relatively small size (4ft x 5.300lb) and mobility allows it to be loaded into a trailer, hike an hour from Davis to Berkeley, and start scanning approximately 30 minutes after it hits the racetrack. .

To date, 36 horses have been scanned in the first six weeks of operation at Golden Gate Fields. All analyzes are performed by a UC Davis team led by Spriet and a Golden Gate Fields team led by Casille Batten, DVM, veterinarian for the Stronach Group. The four balls of a horse can be imaged in 15 to 30 minutes. A new barn has been built at Golden Gate Fields Equine Hospital specifically for PET horses, allowing six horses to be scanned in a single imaging session. Up to 12 horses can be imaged in a day. Two projects, one assessing injured horses and the other showing horses showing no signs of injury, are underway with support from the Oak Tree and Dolly Green research foundations. The two studies aim to compare the results of horses photographed at Golden Gate Fields with those photographed in Santa Anita. As the two sites use different types of running surfaces (i.e., synthetic at Golden Gate Fields and dirt at Santa Anita), these studies will help document and compare the effects of different surfaces on horse bones.

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