Medina Spirit Necropsy Finds No Definite Cause of Death

A necropsy examining the sudden death of Kentucky Derby Presented by Woodford Reserve (G1) first-place finisher Medina Spirit  could not precisely determine why the colt collapsed and died after a Dec. 6 workout at Santa Anita Park, the California Horse Racing Board announced Feb. 11. 

The necropsy was suggestive of acute heart failure without confirmation, participating veterinarians and researchers acknowledged during a press conference following the release of the findings. Horses that die via pulmonary hemorrhage can show similar postmortem characteristics, they added.

Omeprazole, an anti-ulcer medication, and furosemide (Lasix), a diuretic used to control respiratory bleeding, were detected in blood and urine samples consistent with the medication report filed with CHRB by the colt's attending veterinarian, the CHRB reported.

A necropsy is an autopsy conducted upon an animal, performed with the intention to ascertain the cause of death and detect visually apparent abnormalities. They are standard procedures on equines that die at CHRB-regulated facilities, with the California Animal Health and Food Safety diagnostic laboratory system of the University of California-Davis School of Veterinary Medicine undertaking those studies. The CHRB currently lists more than 100 postmortem examination reports on its website, describing necropsy findings, the animal's racing/training history, its veterinary history, and conclusions. 

Medina Spirit was transported to the CAHFS lab in San Bernardino for the necropsy, which included examination of the body and internal organs, and specimen collection for microscopic examination, toxicology, drug testing, and genetic testing. Specimens also were stored for possible future testing. After the examination was completed, Medina Spirit was cremated.

Postmortem examination of Medina Spirit was performed by a diagnostic team at the CAHFS at UC Davis with expertise in pathology, toxicology, and equine drug testing. Involved in the process were Dr. Francisco Uzal, Dr. Javier Asin Ros, Dr. Monika Samol, Dr. Robert Poppenga, and Dr. Benjamin Moeller. Dr. John Pascoe, executive associate dean of the UC Davis School of Veterinary Medicine, working with CAHFS director Dr. Ashley Hill, had administrative oversight.

Zedan Racing Stables' Medina Spirit's sudden death gained national news attention late last year, in part due to the controversy related to the May 1 Kentucky Derby at Churchill Downs.

Post-race test results taken from Bob Baffert-trained Medina Spirit following the Derby showed the presence of the corticosteroid betamethasone, a finding that places him at risk of disqualification after a scheduled hearing with Kentucky stewards Feb. 14. Baffert also could be fined or suspended.

Acting as a private property owner, Churchill Downs Inc. has suspended Baffert from racing at its tracks through the middle of 2023.

Baffert claims Medina Spirit tested positive due to treatment for a skin condition on the colt's hindquarters with the anti-fungal ointment Otomax. His attorneys further argue that Otomax triggered a positive test specifically for betamethasone valerate, which they contend differs from betamethasone acetate. They say the latter is the type of betamethasone given to horses via injections. It carries a recommended 14-day withdrawal time before racing.

Medina Spirit passed tests for prohibited race-day medications during the remainder of his 3-year-old season last year, including in his final race, a runner-up finish in the Nov. 6 Longines Breeders' Cup Classic (G1) at Del Mar. That followed a victory in the Oct. 2 Awesome Again Stakes (G1) at Santa Anita.

Medina Spirit being treated with betamethasone in early spring is unlikely to have played a role in his December death, Moeller and Hill indicated. Moeller said he did not see any evidence to suggest otherwise.

"I would just chime in the typical duration of action for betamethasone is about a week," from the time of administration, Hill added.

"We were hopeful that the necropsy would have revealed more information about the pathophysiology that led to Medina Spirit's sudden cardiac arrest, but it appears that his tragic death was an act of God and was not preventable," Clark Brewster, one of Baffert's lawyers, said in a statement. "As was expected, the necropsy results were compatible with sudden cardiac death and were consistent with reports of similar events of sudden death during workouts.

"Investigators determined that a possible defect in Medina Spirit's cardiac conduction system, which regulates electrical activity in the heart, is a possible explanation. Extensive toxicological testing on multiple samples found no unexpected substances and nothing to suggest that Medina Spirit's cardiac arrest was caused by the use of medications."

Experts say other drugs, such as erythropoietin, also known as EPO, can increase the chance of cardiac arrest, though the necropsy showed no evidence of Medina Spirit having been treated with the red blood cell-building drug. Other than omeprazole and Lasix, no other drugs, heavy metals (including cobalt), or toxicants were detected, according to the CHRB. 

Blood, urine, and aqueous humor samples were screened for the presence of hundreds of substances, both legal medications and prohibited drugs, including, amongst others, EPO, clenbuterol, and betamethasone.

Hair testing was not conducted specifically as part of the necropsy, veterinarians and researchers involved said. Hair samples, collected by CHRB, did not result in a positive test, according to CHRB executive director Scott Chaney. Hair samples were collected in a postmortem examination of Medina Spirit and those samples have been saved.

Pressed by a reporter on the conference call regarding the ability of laboratories to flag all substances that could be in any horse's system, Moeller said the CAHFS-Davis Maddy Laboratory is "well equipped" to test.

"There are always challenges associated with drug testing," said Moeller, the equine chemistry section head analytical chemist at CAHFS-Davis Maddy Laboratory. 

Degenerative joint disease was seen in Medina Spirit's fetlock and elbow joints, the CHRB reported. The microscopic changes in various tissues were mild and did not suggest a specific cause of death, the CHRB noted.

Swollen lungs and foam in the windpipe, an enlarged spleen, and congestion and mild hemorrhages in other tissues seen on the postmortem examination are common in horses dying suddenly, and are compatible with, but not specific for a cardiac cause of death, the CHRB added.  

Samples of heart tissue were sent to the University of Minnesota and to the UC Davis Veterinary Genetics Laboratory as part of ongoing research programs, in collaboration with the CHRB, investigating possible genetic causes of sudden death in racehorses.

At the time of Medina Spirit's death, CHRB equine medical director Dr. Jeff Blea said the causes of sudden deaths are sometimes difficult to determine, with about half remaining a mystery even after further study.

The CHRB echoed those statistics in its Friday release of the Medina Spirit necropsy findings, citing an international study that found that a cause of death related to sudden death was determined with certainty in approximately 53% of cases, a presumptive cause established in 25%, and in about 22% the specific cause of death went undetermined. 

Sudden deaths, classified as having occurred while or shortly after exercise, range from cardiac arrest to hemorrhaging in the lungs and other types of internal bleeding. They account for only a small percentage of equine deaths.

Blea initially was to oversee the necropsy of Medina Spirit before Pascoe fulfilled his role in the necropsy's oversight. Last month, Blea was placed on leave after an administrative law judge suspended his veterinary license following an anonymous complaint to the California Veterinary Medical Board. CHRB chairman Dr. Greg Ferraro called the actions against Blea politically motivated. Blea is now awaiting a full evidentiary hearing.

Beyond UC Davis' oversight, the finalized death report (with the necropsy photographs, microscopic sections, and toxicology and drug testing results) was provided to experts Dr. Laura Kennedy of the University of Kentucky and Dr. Grant Maxie of the University of Guelph, Ontario, Canada, for independent review, the CHRB noted.

"Sudden deaths in racehorses (have) been extremely frustrating for a long time, not just in California but throughout the U.S. and across the world," said Hill during a press conference following the release of the necropsy. "It's a recognized issue that there are horses that just drop dead during the horse working or after exercise. It's been extremely frustrating to try to figure out what's going on."

Medina Spirit was one of two equine fatalities for Baffert at CHRB facilities in 2021, the other fatality being Noodles, who died May 22 at Los Alamitos Race Course from a respiratory ailment known as pleuropneumonia, according to the regulator's online records.

The CHRB previously investigated seven sudden deaths from Baffert trainees from 2011-13 at defunct Hollywood Park and did not find any similarities among the group or a single, identifiable cause. The report and CHRB analysis noted that all Baffert trainees at the time were treated with a thyroid hormone but that it could not be specifically linked to the cluster of deaths.

Dr. Rick Arthur, equine medical director for the CHRB at the time, noted in the report's release in November 2013 that Baffert conducted an internal review of his treatment program and discontinued the use of the thyroid hormone that preceding April.

Levels of thyroxine, a thyroid hormone, were below normal reference limits in the examination of Medina Spirit, though the veterinarians and researchers involved in the necropsy noted that testing for thyroxine can be challenging. Though it can be given to a horse, equines also naturally produce the hormone. 

Many states, including California, have in recent years implemented restrictions on the use of thyroid medication after it became overprescribed, used as a supplement without a horse having an underlying thyroid problem. Thyroid medications can raise heart rates.

The process now continues with the required review of the necropsy report pursuant to CHRB Rule 1846.6, related to postmortem examination review. Based on subject matter expertise, Dr. Alina Vale has been identified as the official veterinarian to perform the review of the Medina Spirit findings.

Additionally, a safety steward and a member of the board of stewards will be assigned to participate in the review. The report will be generated pursuant to the rule and published by the CHRB. Any potential rule violations uncovered in this process will be investigated by the CHRB and would result in a complaint and possible disciplinary action. This process takes place for every fatality occurring at a CHRB-regulated facility.