Gluck | Horse Racing Free Tips

Funds Granted For Follow-Up Study On Catastrophic Racehorse Injuries

Catastrophic injuries in Thoroughbred racehorses is a top concern for the industry and for its fans. That sentiment is shared by researchers at the University of Kentucky's College of Agriculture, Food and Environment, who are working to learn more about changes happening at the cellular level that might indicate an injury is present before it becomes career- or life-ending.

According to Allen Page, staff scientist and veterinarian at UK's Gluck Equine Research Center, a recently completed study submitted for review shows it is possible to identify several early markers for horses at risk of catastrophic injury, possibly allowing for intervention before those injuries happen.

In this initial study, Page and his colleagues analyzed blood samples from more than 1,000 Thoroughbred racehorses. The samples, collected by participating racing jurisdictions from across the country, have come from both catastrophically injured and non-injured horses in a quest to better understand if there are any red flags in horses that suffer a catastrophic injury.

Previous research showed that many catastrophic injuries occur in limbs with underlying and pre-existing damage, leading to the theory that these injuries occur when damage accumulation exceeds the healing capacity of the affected bones over time. As a result, researchers think it is likely there may be markers of this damage that can be detected prior to an injury.

The identification of protein biomarkers for these types of injuries has been explored in previous research with limited success. As a result, the group opted to focus on quantifying messenger RNA gene transcripts or markers, knowing that the results would likely be much more sensitive than measuring proteins.

“We are definitely encouraged by our findings in the initial study. Out of the 21 markers we measured, three of them show real promise as being able to predict injury,” Page said. “Since the ultimate hope is to develop a screening tool that can be used pre-race to identify horses at increased risk for injury, we anticipate adding multiple other markers with our new study that is just getting started.”

As part of their new study, Page and his colleagues plan to utilize RNA-sequencing, a relatively new technology, to expand their search to the approximately 22,000 protein-coding genes horses have. This will dramatically increase the likelihood that they will be able to identify additional markers for horses at risk of injury. They plan to do this by using the large number of samples that have already been collected, further leveraging their initial study and decreasing the amount of time it will take to complete their new study.

The new study has been funded by the Kentucky Horse Racing Commission's Equine Drug Research Council, which also funded the three-year initial study.

“A lot of the credit for these projects goes to the KHRC and the Equine Drug Research Council. Their willingness to fund our projects is really a testament to their interest in supporting innovative and novel ideas geared towards improving the safety and well-being of horses and riders,” Page said.

“I am pleased that the EDRC is able to continue to provide support for this important study and that Dr. Page is able to continue his work on finding ways to protect our equine athletes,” said David Horohov, chair of the UK Department of Veterinary Science.

Joining Page in the research from UK's Gluck Center are Horohov, Emma Adam, assistant professor, research and industry liaison, James MacLeod, John S. and Elizabeth A. Knight chair, and Ted Kalbfleisch, associate professor.

MARS Equestrian Fellow At UK’s Gluck Equine Research Center Continues To Assist Older Horses

Horses aged 15 and over make up between 20 to 30 percent of the United States equine population. An important milestone will be reached this year in the quest to learn more about this population. October marks the one-year anniversary of Amanda Adams, associate professor at the University of Kentucky Gluck Equine Research Center specializing in aged horse research, becoming the first MARS Equestrian Fellow. This fellowship supports her work to improve not only how the industry cares for senior horses but also how veterinarians can better diagnose the conditions and diseases that affect them.

According to Linda Mars, gaining a better understanding of how nutritional and management requirements change with age and activity will help the industry provide the best possible care to horses and ponies throughout their lives.

As horses age, they face an increased risk for some common conditions and diseases. One of those, pituitary pars intermedia dysfunction, develops in approximately 20 percent of senior horses. Another condition, equine metabolic syndrome, is associated with insulin dysregulation and often obesity. This can occur in all aged animals but may have additional adverse consequences in the older horse. Both are associated with the development of laminitis, a very painful and debilitating condition of the hoof that is often life ending.

These are just two of the key problems that Adams' team has been able to work on with MARS Equestrian support. Her team has established and maintains a unique herd of nearly 80 aged, obese and metabolic syndrome horses. The herd is the only one of its kind in the U.S., and it provides unique opportunities to study geriatric and endocrine diseases in horses.

According to Adams, most of what her team knows and what they are learning about aging and endocrine diseases in this population of special needs horses wouldn't be possible without access to this research herd.

“In a short period of time, we have made major breakthroughs in gaining a better understanding of how to nutritionally manage horses suffering from insulin dysregulation, specifically in equine metabolic syndrome horses. We are also learning that the season has a profound influence on the metabolic responses of these diseased horses, which will help shed light on why these horses may develop laminitis at certain times of the year,” said Adams, a faculty member of the UK College of Agriculture, Food and Environment. “Over the last year, we have also been working to define sarcopenia (an age-related loss of skeletal muscle mass and strength) in aged horses and how specific diet and exercise routines may reverse or improve that muscle loss. Furthermore, we are studying what effect exercise has on the inflammation-aging response in aged horses.”

While the progress is promising, Adams said that more work is needed. In addition to learning how to better manage these horses, there is a need at the basic scientific level to understand how the aging process affects the horse's immunity, metabolic status and nutritional needs.

“The many problems we face with the aging horse are important given the growing senior horse population,” said Pat Harris, Director of Science, MARS Horsecare. “Thus, it is critical that we continue these efforts to advance the field and improve our knowledge in senior horse care,” “ultimately creating a better world for horses” added Bridgett McIntosh, Director of MARS Equestrian.

New Study Shows Last Line of Defense Against Equine Parasites Beginning To Fail

New research shows that ivermectin and moxidectin dewormers are losing their efficacy again small strongyles. This is particularly troublesome as these drugs are the last lines of defense against the worms and no new dewormers are in the research pipeline.

The study was the first in the world to confirm small strongyle resistance through repeated testing. Resistance to two of the three deworming drug classes was confirmed years ago and it was predicted that small stronglyes would become resistant to macrocyclic lactones, a class of dewormers of which ivermectin and moxidectin are a part.

The study team included Dr. Martin Nielsen, Professor of Equine Infectious Disease at the M.H. Gluck Equine Research Center, Michael Banahan of Godolphin's Jonabell Farm in Kentucky, and Dr. Ray Kaplan, parasitologist in the Department of Infectious Diseases at the College of Veterinary Medicine at the University of Georgia.

The team found that the efficacy of both ivermectin and moxidectin were reduced in a group of 50 imported Irish Thoroughbreds, though 50 US-bred horses on the same farm had no such resistance. The farm rigorously followed current guidelines for deworming and pulled fecal egg counts on all horses on the farm multiple times.

The horses were dewormed and tested multiple times over an eight-month period. The team concluded that the resistance to ivermectin and moxidectin was imported with the Irish horses. They note that this demonstrates how quickly resistant parasites can spread across the globe. They encourage farm and horse owners to utilize fecal egg count tests and to stringently follow deworming guidelines to attempt to increase the longevity of the efficacy of ivermectin and moxidectin.

Read the study here.

Promising Developments In Quest To Prevent Catastrophic Racehorse Injuries

Catastrophic injuries in Thoroughbred racehorses is a top-of-mind concern for the racing industry and for its fans. That sentiment is shared by researchers at the University of Kentucky, who are working to learn more about the changes happening at a cellular level that might indicate an injury is present before it becomes career or life ending.

Might it be possible to identify an early marker or signal for horses at risk of catastrophic injury, allowing for intervention before those injuries happen? And, if yes, might this type of detection system be one that could be implemented cost effectively on a large scale?

According to Allen Page, DVM, PhD, staff scientist and veterinarian at UK's Gluck Equine Research Center, the short answer to both questions is that it looks promising.

For the past three years, Page, along with UK colleagues, has been analyzing blood samples from more than 1,000 Thoroughbred racehorses. The samples, collected by participating racing jurisdictions from across the country, have come from both catastrophically injured and non-injured horses in a quest to better understand changes that might be happening at the cellular level during racing and if there are any molecular red flags which consistently differentiate horses that suffer a catastrophic injury.

An abstract of this research will be presented at the American Association of Equine Practitioners' annual meeting in December and more information about the study's findings will be shared this fall.

“We are definitely encouraged by our findings,” Page said. “The ultimate hope is, of course, to develop a screening tool that can be used pre-race to identify horses at increased risk for injury. The results of this study suggest that analysis of messenger RNA expression could be an economical, effective and non-invasive way to identify individual racehorses at risk for catastrophic injury.”

This study, as well as a follow up study beginning this month, has been entirely funded by the Kentucky Horse Racing Commission's Equine Drug Research Council.

“It is hard to overstate how much we appreciate the continued support of the KHRC and the Equine Drug Research Council. Their willingness to fund these projects is really a testament to their interest in supporting innovative ideas geared towards improving the safety and wellbeing of horses and riders,” Page said.

David Horohov, PhD, chair of the Department of Veterinary Science, director of the Gluck Center and Jes E. and Clementine M. Schlaikjer Endowed Chair, echoed those sentiments, “I am pleased that the EDRC is able to continue to provide support for this important study and that Dr. Page is able to continue his work on finding ways to protect our equine athletes.”

Joining Page in the research from UK's Gluck Center are Emma Adam, DVM, PhD, DACVIM, DACVS, assistant professor, research and industry liaison, Horohov, James MacLeod, VMD, PhD, John S. and Elizabeth A. Knight chair, director of UK Ag Equine Programs and professor of veterinary science and Ted Kalbfleisch, PhD, associate professor.

Previous research has shown that many catastrophic injuries occur in limbs with underlying and pre-existing damage, leading to the theory that these injuries occur when damage accumulation exceeds the healing capacity of the affected bones over time. Since many of these injuries have underlying damage, it is likely that there are molecular markers of this that can be detected prior to an injury.

The identification of protein biomarkers for these types of injuries had been explored in previous research, albeit with limited success. The focus of this project, measuring messenger RNA, had not yet been explored, however. The overall objective was to determine if horses that had suffered a catastrophic injury during racing would show increased inflammatory mRNA expression at the time of their injury when compared to similar horses who were not injured. It turns out that this theory might be on to something.

Messenger RNA (mRNA) is a single-stranded RNA molecule that is generated from DNA through the process of transcription. This mRNA carries the genetic information specifying a particular amino acid sequence, which can then be used to create a protein through the process of translation. While work looking at inflammation often involves measuring proteins, Page and his collaborators opted to focus on mRNA due to the limited availability of reagents available to measure horse proteins and concerns about how limited the scope of that research focus would be. Focusing on mRNA expression, however, is not without issues.

According to Page, mRNA can be extremely difficult to work with. “A normal blood sample from a horse requires a collection tube that every veterinarian has with them. Unfortunately, we can't use those tubes because mRNA is rapidly broken down once cells in tubes begin to die. Luckily, there are commercially-available blood tubes that are designed solely for the collection of mRNA,” he said.

“One of the early concerns people had about this project when we talked with them was whether we were going to try to link catastrophic injuries to the presence or absence of certain genes and familial lines. Not only was that not a goal of the study, the samples we obtain make that impossible” Page said. “Likewise for testing study samples for drugs. The tubes do an excellent job of stabilizing mRNA at the expense of everything else in the blood sample.”

Horses eligible for inclusion in this study were Thoroughbreds entered into any race in one of five participating jurisdictions from September 2017 to June 2020. To look at the mRNA, these jurisdictions collected specific blood samples either pre-race or post-race from a selection of non-injured horses or immediately from a horse after a catastrophic injury. Once collected, samples were sent in batches to the Gluck Center where they were analyzed using quantitative PCR (qPCR). The names and category (injured, pre-race or post-race) of sampled horses were kept from the researchers by participating jurisdictions until the samples had been fully analyzed.

Once the names and dates of samples were revealed, public records were used to learn more about each horse. Information examined included the horse's sex, age, race type and whether non-injured horses raced again within three months of the sampled race. For horses who had been injured, more information about the race itself was gathered to determine if there were other factors related to the injury. Additionally, necropsy results, when available, were used to categorize the type of musculoskeletal injury that occurred.

“As of right now, there are four mRNA markers, out of the 23 we have measured with qPCR, that show some significant promise as markers for identifying horses at risk of a catastrophic injury. Obviously, there has been an impact of COVID-19 on our research, so there are still a few more samples to process and add to our data analysis. Once we do that, we plan to submit the findings for publication. Currently, we're targeting the end of the year to be able to share exactly what we have found so far” Page said.