The 2019 allotment of $1,338,858 will fund eight new projects at seven universities, nine continuing projects, and three career development awards. The 2019 slate of research brings Grayson-Jockey Club Research Foundation’s totals since 1983 to more than $27.5 million to underwrite 366 projects at 44 universities.
Musculoskeletal injuries cause 80-83% of deaths in racing and training [1-4]. Bone fracture is the most common fatal injury; the proximal sesamoid bones (PSBs), located in the fetlock joint, fracture the most often, accounting for 50-60% of all fractures . Due to the PSBs location, there is no reliable way for veterinarians to determine if an animal is at risk for fracture before an event. Therefore, methods to predict and prevent PSBs fracture are needed.
To prevent bone fractures, we must understand how bone fractures develop in racehorses. We know that bone fractures rarely occur from a single bad step in athletes. Instead, fractures are the result of multiple factors that affect the accumulation of bone damage over racehorses’ careers. These factors are related to the distances that racehorses train and race, the speed of the horse during training and racing, and the stiffness of the race surface that training and racing occur on. Horses with PSB fractures spend more time in active training and racing, complete more events, train and race longer since last layup, have higher exercise intensities 6 months prior to death, and have greater cumulative career distances than other racehorses.
Damaged bone can heal if given enough time; therefore, the weekly timing of works and races plays a large role in racehorses’ susceptibility to injury and bone fracture. Further, these factors interact with, and affect, each other over time. In order to understand the impact of training schedules and race surface properties on racehorses’ susceptibility to injury over time, the complex interaction of gait, speed, distance, and timing of exercise; alterations of limb loading due to race surface properties; and the time course of removal of damaged bone and the inherent time lag in the replacement by healthy new bone – must be understood. The complexity of the relationships require computer modeling approaches that take into account the time sensitive nature and interaction of the events to understand the resultant risk for injury.
The goal of this research project is to enhance a finite-element computational model of Thoroughbred PSBs to predict fracture risk based on an animal’s training history. The program uses training history (number of races, distances, etc.), race surface information, and a mathematical model of bone’s innate repair processes to predict damage levels in PSBs. These damage levels can then be related to fracture risk. This research proposal’s focus is on exercise and race surface as risk factors since both can be modified for the prevention of injury.
This project has three main steps (aims). Aim 1 is to calibrate our existing finite element (FE) model that uses training and race history as input factors to predict PSB damage, healing, and porosity, with PSB porosity and microdamage data collected from 20 case and control TB racehorses. Aim 2 is to test the model’s ability to predict PSB fracture using existing exercise history data from 392 TB racehorses and make necessary modifications to the model for the general racehorse population. Aim 3 is to determine what constitutes a “high fracture-risk” exercise program by determining the relative contributions of training regimen and exercise surface to the predicted PSB fracture-risk.
One of the most important and common classes of diseases affecting horses are gastrointestinal (GI) diseases including colic and colitis. Despite tremendous research efforts to both diagnose and prevent these diseases, they remain very common and frequently are not diagnosed until severe disease is present. One area that is gaining recognition as an important player in equine GI health and disease is GI bacteria or the microbiota. The microbiota consists of all of the bacteria and other microorganisms in the GI tract. Alterations in the amounts and types organisms that make up the microbiota have been linked to both GI and non-GI diseases of horses including colic, colitis, laminitis, and obesity. These findings are part of the reason why there are a vast array of prebiotics, probiotics, and other products on the market that claim to influence the GI microbiota.. Unfortunately, there is minimal evidence to support the efficacy of these products and a lack of understanding of how these products work. A major contributor to the lack of evidence and understanding of these products is related to an inability to monitor the health and function of the equine GI tract. It is clear when severe disease is present but currently impossible to monitor subtle changes. Similarly, while we can easily diagnose severe inflammation and microbiota changes during disease, we cannot capture the changes that occurred prior to clinical disease. These limitations result in capturing results of GI injury and disease but not causes. Consequently, there is great need for improved understanding of the causes of disease and early identification of horses at-risk of developing GI disease. In the absence of such knowledge, effective intervention strategies to reduce GI and GI-related health risks will remain elusive.
Horses and other animals naturally shed cells lining the GI tract on a daily basis. People, in fact, shed up to 1/3 of the cells lining their GI tract daily. We have developed a technique for examining the gene expression profile of these cells to monitor the health and function of the GI tract from fecal samples. We have shown that this approach offers a promising means to non-invasively examine the response of the GI intestinal tract to injury. Further, we have convincing preliminary data demonstrating that the gene expression profile arising from these cells mirrors the gene expression profile of the tissues within the GI tract of the horse and provides a global view of the health and function of the GI tract. This approach offers a highly attractive, non-invasive means of monitoring GI responsiveness to disease and interventions. Thus, our long-term goals are to 1) develop inexpensive, non-invasive diagnostic tests in order to document GI inflammation prior to the onset of severe disease in horses; and, 2) by examining host and microbiota data simultaneously we aim to elucidate the mechanisms of host-microbiota interactions in the context of health and disease. Ultimately, we aim to use this approach to identify specific pathway by which the host and microbiota interact so that this critically important interaction can be targeted therapeutically.
In order to achieve our goals, we will utilize a reversible model of GI inflammation with which we have extensive experience. We will induce GI inflammation with the non-steroidal anti-inflammatory drug (NSAID) phenylbutazone and noninvasively interrogathost response and response of the microbiota. Importantly, we will collect samples sequentially both before and after induction of inflammation in order to gain predictive and diagnostic information about GI inflammation in horses. This approach will have broad application to many equine intestinal disorders and will provide the much needed mechanistic insight into disease development and progression, thereby enabling us to develop effective prevention and treatment strategies for equine GI disease.
In recent years the use of antibiotics has led to an increasing incidence of infections with multidrug resistant (MDR) organisms. The rapid development of resistance to newly developed pharmacologic drugs necessitates the advancement of novel therapeutic strategies. Stem cell based therapies are particularly attractive as an alternative to traditional antimicrobials as they are readily available for harvest and expansion in vitro and may enhance the activity of conventional antibiotics as they are not subject to development of resistance. Mesenchymal stem cells are part of the normal tissue components of healing and repair, and have been demonstrated to have both direct and indirect antimicrobial properties. Mesenchymal stem cells are thought to be antimicrobial in action directly by secreting antimicrobial proteins and indirectly by enhancing the response of the body’s immune system.
We hypothesize that using MSC therapy in combination with conventional antibiotic therapy will result in enhanced immunomodulation thereby improving clinical outcomes by reducing inflammation and morbidity associated with infection. Furthermore, we hypothesize that utilizing MSC therapy in combination with conventional antibiotic therapy will result in enhanced antimicrobial effect and improved infection control by affecting biomarkers of inflammation and infection. We will test these hypotheses by assessing the use of MSCs in an equine model of septic arthritis to determine if MSCs reduce inflammation and bacterial colony counts and increase the effectiveness of antibiotics in equine joint infections to allow successful eradication of infection and reduction of inflammation.
Systemic antibiotic therapy for the treatment of equine ascending placentitis frequently fails to clear bacteria from the uterus and fetal membranes, resulting in an ongoing nidus of infection, and continuous protected source for reinfection of the foal. As a result, treatment success is poor. Local treatment with a broad-spectrum antibiotic formulation with good activity in the presence of suppurative inflammation may eliminate bacteria from the cervical star region, enabling systemic therapy to effectively treat fetal infection, and reduce the inflammatory processes. Work in our laboratory has demonstrated that a procaine penicillin/gentamicin formulation is able to eliminate growth of Streptococcus equi subsp. zooepidemicus in uterine purulent fluid at dilutions of up to 1:100, and further suggests that this antibiotic combination can be safely administered to pregnant mares as a trans-cervical intrauterine infusion. Therefore, we propose to compare the antibiotic activity and tissue concentrations of two formulations of commercially available penicillin and gentamicin, and to determine whether addition of a single trans-cervical treatment can augment systemic therapy to improve foal survival and health.
Thoroughbred racehorses can be considered elite athletes with high demands placed on their joints and bones. Race training is associated with repetitive stress much like the human runner. The body is capable of adapting to such stress overtime by gradually increasing the thickness and stiffness of areas of bone undergoing the greatest amount of stress. However, this adaptive system can be overwhelmed such that microfractures begin to develop. This is often referred to as maladaptive stress remodeling. If the cycle of repetitive stress does not cease, microfractures can lead to stress fractures or collapse of the joint surface. Unfortunately, some stress fractures can be catastrophic in the racing Thoroughbred. Additionally, collapse of the joint surface can lead to irreversible joint disease or osteoarthritis.
Diagnosing horses early in the process of maladaptive stress remodeling is extremely challenging. Plain radiographs are not sensitive enough to identify subtle changes in bone that may be suggestive of microdamage. Computed tomography (CT) is the best tool for evaluating bone; however, CT imaging of the limbs needs to be performed with the horse under general anesthesia. Magnetic resonance imaging (MRI) is also more sensitive than plain radiography; however, many MRI machines require general anesthesia, while standing MRI scans are time consuming (60-90 minutes). Recently, a new technology has emerged that allows a CT scan to be performed in the standing, sedated horse in a matter of seconds. Robotic arms that navigate a 360o path around a particular site on the limb acquire the CT images. The images are then reconstructed using advanced motion correction software and reconstruction software.
Over the past two years, New Bolton Center has been performing CT scans on standing, sedated horses, with the majority of scans being performed on the fetlock joints of Thoroughbred racehorses. We have been able to produce high-quality images of the fetlock joints in clinical cases using the robotic CT. In this research proposal, we are aiming to perform standing CT scans on young Thoroughbred racehorses during their first year of training such that we can begin to identify early changes in bone that may lead to pathology. In addition, we propose to collect blood samples during the 12-month study period for the purpose of identifying blood markers that may be affected by training. We are very fortunate to have full funding provided by the Pennsylvania Racing Commission to collect blood samples during the 12-month study period for the purpose of identifying endogenous bone and inflammatory biomarkers.
The overarching goal of this research is to assess robotic CT and paired blood analysis as an early screening tool for the development of bone injury such that horses can be treated before irreversible damage or catastrophic injury occurs. In the first aim, we will use robotic CT, to evaluate changes in the bones of the fetlock joint during the first year of race training in young (2-year-old) Thoroughbred racehorses. Horses will be enrolled before they begin race training as 2-year-olds and will have CT scans performed at 0 months (pre-training), 6 months and 12 months. In the second aim, we will collect blood samples from the same group of Thoroughbred racehorses undergoing CTs throughout their first year of training. We will measure changes in blood levels of osteocalcin (a marker of bone growth) and CTX-I (a marker of bone breakdown), as well as blood markers of inflammation.
Equine herpesvirus type 1 (EHV-1) is a major infectious agent, causing outbreaks of abortion, respiratory and neurologic disease worldwide. Infection may require horses to be put down or permanently affect performance. Veterinary care and quarantine costs have a large economic toll on the racing industry. Most horses are exposed to EHV-1 after birth, however immunity does not last long. We currently vaccinate “at-risk” horses against EHV-1, such as pregnant mares and horses in an outbreak. Of the killed and modified-live virus (MLV) vaccines available, the MLV vaccine affords the best protection. However, protection is still incomplete and vaccinated horses still become infected. Vaccine research has focused on modifying the virus, with few successes. The horse’s immune system, which fights off the virus, has been neglected. A better knowledge of immunity may help us identify why protection is not long-lasting and design better vaccines.
The goal of vaccination is to “train” the immune system to recognize and destroy invading viruses. This proposal is focused on B cells, which secrete proteins called antibodies (Abs) that recognize and bind to foreign proteins or antigens on viruses. B cells react to viral antigens by modifying their genes, selecting specific sequences to produce Abs against the virus. Each Ab produced by a single B cell has a unique sequence called an antigen recognition sequence, because it is the part of the Ab that recognizes and binds to a specific antigen. Because the virus contains many antigens, B cells produce a vast array of Abs, all of which have unique sequences from their gene rearrangements. However, only a few of these Abs can bind to and neutralize virus, i.e. are protective. Such protective Abs are important because they prevent the virus from spreading to and infecting other cells or horses. Recently, a class of very potent and highly effective Abs, termed broadly neutralizing Abs (bnAb), have been discovered in people against highly pathogenic viruses like flu and Ebola. With advances in technology, such as high-throughput mRNA sequencing, we can now synthesize these bnAbs in large quantities in the laboratory and use them to treat sick patients (called passive immunotherapy). This treatment saved lives in the Ebola outbreaks in Africa. These bnAbs are also driving discovery of new vaccine targets for various human viruses.
Currently, we only track how B cells are responding to EHV-1 by measuring overall or total Ab levels in blood, but we don’t know which of these Abs are protective. There are also no known bnAb against EHV-1 – in fact, we do not have any individual or monoclonal Abs that can neutralize EHV-1. The goal of this study is to use mRNA sequencing to get a global picture of the B cell response to EHV-1 and yield a large sequencing database of Abs produced by B cells after EHV-1 MLV vaccination. From this database, we hope to discover new protective Abs against EHV-1, which, in turn, will help us design better vaccines. Hypothesis: Vaccination with EHV-1 will drive a unique pattern of B cell responses that can be detected by high-throughput mRNA sequencing of individual B cells in blood. Aim 1: To uncover the blood B cell response to vaccination with EHV-1: We will vaccinate 3 horses with MLV EHV-1. Horses will be boosted 30 days after the 1st vaccination to amplify the B cell response. We will collect blood before vaccine 1 (Abs present before vaccination), before vaccine 2 (Ab production underway), and 7 (small boost in Abs) and 21 (peak Ab production) days after vaccine 2.
We will then use a novel technique, called Droplet-Assisted-RNA-Targeting by single cell sequencing (DART-seq), developed by Dr. De Vlaminck, to obtain the sequences of individual B cells. With this technique, blood B cells are sorted into a single oil droplet with a barcoded microbead in a microfluidic device. The microbeads contain primers which bind to the antigen recognition sequences of the Ab mRNA and a unique molecular identifier which quantifies the mRNA. Dr. Felippe has primers in hand for the horse Ab sequences. From the mRNA, we create a copy DNA library, which is then sequenced. Using specialized computer programs, we will link each sequence to one B cell, thus obtaining and quantifying the complete sequence of the antigen recognition region of the Ab in thousands of B cells. As a sub-Aim, we will then select 1-2 sequences from each horse to generate equine-based Abs in the laboratory and test them for reactivity against EHV-1. Drs. de Vlaminck and Danko used DART-seq to obtain such Ab sequences from healthy people and Dr. Parker has made a cat-based Ab, so our team is set to succeed. Our ultimate goal is to identify and manufacture new monoclonal equine-based Abs that neutralize EHV-1.
This project aims to identify changes in stride characteristics in racehorses that are associated with increased risk of injury, fatality or poor performance.
One of the greatest dangers to the existence of horse racing is the loss of public confidence that occurs as a result of racehorse injury. Musculoskeletal injuries to racehorses are the most common cause of training failure and wastage, and account for upwards of 80% of fatalities. Further, most racehorse catastrophic injuries are due to fatigue of bone, evidenced by the high proportion of pre-existing pathology found at postmortem. Not only this, racehorse injuries may result in serious jockey injury, and substantial insurance costs. Development of evidence-based strategies that reduce racehorse injury rates will therefore have a significant and positive impact on the industry.
The risk of racehorse injury is multifactorial. Management, environmental and horse-level risk factors have been established in numerous studies worldwide. These include race type, race distance, track surface, horse age, prior injury, previous race history, recent lameness, and frequency, intensity and duration of exercise. These latter factors indicate that workload influences the onset of bone fatigue, and repeated or high impact loadings may cause complete failure. Quantitative measures of stride characteristics such as speed, and stride length and count, are good indicators of exercise workload. Further, divergence from normal galloping stride patterns are possible to identify. In lame horses, and in those restrained by their rider, limb velocity has been shown to be higher than horse velocity due to the decrease in stride length and stride time. However, there is some uncertainty as to which characteristics are the most important, and how these factors interact with each other to cause fatigue of bone. Progress in understanding these complex interactions has been slow, predominantly due to the time consuming and expensive nature of clinical trials using racehorses, the small sample sizes, and the impracticality (and risk of potentially detrimental outcomes) of implementing intervention studies on racehorses in training. Information about high-speed exercise history (workouts and races) has been readily available for the last few decades. However, these histories generally only contain information on the frequency of such high-speed exercise and the distances worked or raced. Previous studies have provided averages for stride length and speed, and have not yet investigated within and between horse and race variations. With more advanced technology, we can now quantify these workloads more accurately and for each individual racehorse over time. Such quantitative measurements, particularly of velocity (speed) and distance, have been advocated by consensus as the way forward for future scientific studies.
To this end, the proposed research will take advantage of a large-scale database containing five years of continuously recorded measures of stride characteristics during Thoroughbred races. Our goal is to identify key stride characteristics that may be associated with increased risk of injury, fatality or poor performance. This research will help us gain a better understanding of horse-level parameters that contribute to higher rates of injury, thus benefiting the racing and equestrian industries.
The specific aims of this proposed research project are to: (1) determine the characteristics of strides for different styles of racing, and variation within these groups of racehorses; and (2) identify key racing styles and changes in stride characteristics that are associated with the occurrence of race-day injuries or fatalities, or with poor performance. The findings from this research will be used to develop strategies aimed at reducing the incidence of racehorse injuries and fatalities.
To achieve these specific aims, data on race-day injuries and fatalities, race fields, and stride characteristics will be merged. The stride characteristics have been collated for 2011 to 2016 racing seasons by StrideMASTER, a company that employs a tracking system using GPS and precision sensors on race days in Tasmania, Australia. Information on 33,460 starts in 2,931 races held at 354 race meetings will be utilized. Advanced epidemiological methods will be used to identify different clusters of styles or patterns of racing as well as to model the effects of changes to these patterns using Cox proportional hazards models.
Catastrophic breakdowns of the lower limb are the most common cause of horse fatalities on the racetrack. The fetlock is the region most frequently involved in catastrophic breakdowns due to fractures. Imaging techniques such as bone scans, computed tomography (CT scans) and magnetic resonance imaging (MRI), have improved the ability to detect injuries that predispose to breakdown when compared with X-rays but many limitations remain. Currently it is still not possible to confidently identify horses at risk for breakdown. Improving the detection of signs that precede breakdown is extremely important in order to reduce the number of accidents on the race track.
Positron Emission Tomography (PET) is an imaging technique that has recently become available for horses. PET relies on the same concepts as a bone scan commonly performed on racehorses and people: a small amount of an injected radioactive tracer concentrates in abnormal areas in bones, leading to the identification of bone injuries. The main difference between PET and a regular bone scan is that PET provides 3-dimensional information with higher resolution, providing precise localization of abnormalities. This allows improved recognition of early injuries that precede breakdowns, as confirmed in a recent study in nine racehorses. The main limitation of the current PET scan technique is the need to anesthetize the horse to obtain images.
To avoid the risks associated with general anesthesia, we have designed a PET system to obtain images in standing horses using only a sedative or tranquilizer. The scanner model previously used is being modified to orient in a way to allow positioning around the limbs of a standing horse. The new scanner has been designed with a ring of detector that opens freely to allow easy positioning and safe release if the horse moves. This important safety concept has been validated with a mechanical prototype of the new scanner.
We believe that this new scanner will be safe and easy to use on horses and provide images that will detect more injuries when compared with regular bone scans. Study Part 1 will validate the new PET scanner by comparing image quality of PET scans obtained from standing and anesthetized research horses at UC Davis. Study Part 2 will be a clinical trial comparing findings from bone scan images and standing PET scan images of racehorses at Santa Anita Racetrack. We expect that more abnormalities (injuries) will be detected using PET scan than bone scan. PET scans will be repeated at 6 and 12 weeks to assess changes after treatment or rest.
Pneumonia caused by a bacterium called Rhodococcus equi (R. equi) is an important cause of illness and death in foals. Because no vaccine is available and because many foals are unable to fight infection on their own, control of R. equi pneumonia is based on treatment of foals with a specific class of antimicrobials (named macrolides). With extensive, repetitive use of macrolides, these bacteria become resistant to this group of antimicrobials. The lack of alternative antimicrobials that would efficiently kill R. equi, and the low likelihood of novel antimicrobial development indicate that new approaches to control are needed. The specter of antimicrobial resistance is a major problem for human and veterinary medicine.
We propose to use a self–cure strategy (named host–directed, where the foal is the host) to reduce the occurrence and mortality of R. equi pneumonia, and to decrease the chances of development of antimicrobial resistance. Foals appear to be infected with R. equi during the first weeks after birth, a period which precedes complete development of adaptive immunity (the type of immune response made of specialized cells, such as antibody–producing cells). Foals are born with a functional innate immune system, comprised of cells which respond to all invading organisms. Stimulation of innate immunity, therefore, is a logical approach for protecting foals. Some molecules located on the surface of innate immune cells, called Toll–like receptors or TLRs, are important mediators of innate immunity. They act primarily through secretion of substances called cytokines. PUL–042 is a product that combines two substances that can stimulate innate immunity via TLRs directly that can be inhaled into the lungs to prevent bacterial pneumonia, and we plan to investigate its use as a method of host–directed control of R. equi pneumonia. We propose to use this product via nebulization, which is the administration of mist inhaled into the lungs using a nebulizer (such as those used for asthma patients). The objectives of our proposal are to better understand the how the infection of R. equi occurs in lung cells of both horses and foals (Year 1), and to evaluate if nebulized PUL–042 is safe and if it increases the capacity of equine lung cells to kill R. equi (Year 2).
Our long–term goal is to demonstrate that PUL–042 nebulization of foals could be used at equine breeding farms to prevent pneumonia caused by R. equi. Once optimized, this approach could replace antimicrobial prophylaxis (a strategy in which antimicrobials are used to prevent the disease by treating the foals that are not sick). Furthermore, it might serve as a supplementary treatment to antimicrobials therapy in foals with R. equi pneumonia, which could potentially shorten treatment time and improve outcomes. The current standard for prevention of R. equi pneumonia at farms is transfusion of R. equi hyperimmune plasma. This approach has many disadvantages, such as being expensive, labor–intensive, and causing undesired side–effects in foals. Nebulization of PUL–042 could replace plasma transfusion. Last, by stimulating innate immune responses of the newborn foal, a reduction of other bacterial respiratory infections (e.g., the bacterium that causes strangles) might occur, as well as improved responses of foals to vaccines. Results of this project will have tremendous impact for the equine industry, specifically at horse– breeding farms where R. equi pneumonia can occur in 20–40% of the foal crop.
Veterinary interpretation of certain findings on pre-sale radiographs often varies and this is a continued source of controversy within the Thoroughbred industry. We currently have insufficient information relating to sesamoiditis and stifle lucencies for veterinarians to give objective advice on the true significance of these lesions, and the risk of associated problems as the horse enters training. Present uncertainty over the meaning of these findings can negatively impact the sale of young horses and causes frustration amongst breeders, consignors, buyers and veterinarians. Veterinary advice that deems these findings an increased risk for resale makes pinhookers reluctant to bid on affected horses, therefore leaving the sellers to count solely on the interest of buyers looking to retain horses to race themselves. This drastically weakens the marketplace and negatively impacts the whole industry. In order to turn this around and enable the repository system to function as it was intended to strengthen the industry; our research group believes that a large-scale scientific investigation into the significance of sesamoiditis and stifle lucencies in sales Thoroughbreds is needed.
Suspensory branch ultrasonography is becoming more frequent in sales yearlings, as sellers and buyers sensitized to the issue of sesamoiditis seek to gather more information on which to base their decisions. Ultrasonography is being performed on yearlings with radiographic signs of possible sesamoiditis, as well as on valuable yearlings that have a radiographic sesamoid appearance considered to be within normal limits. As pre-sale suspensory branch ultrasonography is becoming commonplace, it is critical that evidence-based research be performed to provide objective data to explain the long-term significance of varying degrees of ultrasonographic findings.
This research will investigate both sesamoiditis and medial femoral condyle lucencies in sales horses, on an unprecedented scale. Researchers will gather radiograph and ultrasound information on a large number of sales yearlings and two-year-olds and then follow these horses into their racing careers. Researchers will analyze which, if any, changes seen on sales radiographs and ultrasounds are predictors of clinical injury or compromised racing ability, compared to other horses without these radiograph findings. Consignor permission for research inclusion was granted for 74% of yearlings at the 2016 Keeneland September Sale, showing an overwhelming desire for information to sort out these issues. Researchers will evaluate the radiograph information on these 2975 yearlings, combined with the ultrasound information on 704 of these yearlings. Permission for inclusion in the two-year-old phase of the study was granted by 45 two-year-old consignors, for 78% of eligible horses. Therefore, the yearling information will be paired with two-year-old sales radiographs on 473 of these same horses, and two-year-old sales ultrasounds on 415 of these horses, for those which presented at the five major 2017 two-year-old in training sales. Horses will then be followed into their two and three-year-old racing seasons.
The ultimate goal of this research is to provide the industry with a better understanding of sesamoiditis and stifle lucencies in Thoroughbreds. With the knowledge gained from large-scale scientific research, the information on pre-sale radiographs should allow the seller and prospective buyers to work with veterinarians to make informed decisions on the trade and future racing management of sale horses. Individual horses will benefit through appropriate management tailored to any significant abnormalities that have an increased risk of injury during training. The industry as a whole will benefit through increased knowledge and confidence in decision making surrounding bloodstock purchases and management. This will boost industry-wide confidence in the sales repository system and in the veterinarian’s role in the trade, management and care of the Thoroughbred horse.
Horses, like people, commonly suffer from asthma. In fact, it is the second most common cause of disease in athletic horses including young Thoroughbred racehorses. While the condition causes decreased performance, it is difficult to detect. Affected horses typically train well and may only cough occasionally. The best way to detect equine asthma is by visualization of excess mucus by endoscopy of the airways after exercise or by identification of airway inflammation by lung wash. Asthmatic horses can be treated with anti-inflammatory drugs (corticosteroids); however, treatment may not be effective, and the risk of residue resulting in a positive drug test is always a concern.
Exposure to dust in the stall, particularly from hay, is likely an important contributor to the onset of equine asthma. Feeding horses steamed hay or grass silage (haylage) is an effective way to decrease dust levels; however, it is unknown if it would be sufficient to control airway inflammation in asthmatic racehorses. The body has natural ways to resolve inflammation by using compounds present in the diet, such as omega-3 fatty acids, to decrease inflammation and heal tissue. Fresh grass and haylage have high levels of omega-3 fatty acids compared to dry hay. Racehorses and Sport Horses typically are fed dry hay and do not have access to fresh grass. Consequently, in addition to lowering dust levels, feeding haylage to racehorses may provide additional benefits compared to steamed hay due to higher omega-3 content.
The goal of the study is to compare the effect of feeding dry hay, steamed hay, or haylage on dust level, airway inflammation and blood omega-3 levels in Thoroughbreds actively racing in Indiana. We hope to find that horses fed haylage or steamed hay will be exposed to lower levels of dust, resulting in decreased airway inflammation compared to horses fed dry hay. In addition, we believe that haylage will result in the most significant improvement, and this will be associated with higher blood levels of omega-3 fatty acids.
Horse asthma is the second most common cause of disease in young Thoroughbred racehorses after bucked shins. Affected racehorses are commonly treated with anti-inflammatory drugs and antibiotics, despite only weak evidence to support their use. Drug elimination times are poorly documented, thereby presenting a risk of being detected during drug testing. Therefore, there is considerable interest in resolving lung inflammation without drugs. The purpose of the study is to compare the effect of dry hay, steamed hay and haylage on lung health of racing Thoroughbreds. If the study demonstrates that low-dust forages such as haylage and steamed hay help reduce asthma severity in racehorses, it would potentially be a major benefit to horses’ health and welfare and to the equine industry.
Maladaption to training syndrome is characterized by the increase in a specific enzyme, y-Glutamyl-Transferase (GGT), in the blood of racing Thoroughbreds. It is currently unknown what causes the abnormally high enzyme and if it is the cause of the poor performance of affected horses. We seek to shed light to the possible causes and will test different potential factors that may help us explain this syndrome in this study so that we can help prevent or treat the affected horses.
The first factor could be a metabolic problem that causes horses to have high GGT activity and makes them less able to respond to the challenge of a race. This may be due to the fact that strenuous exercise can lead to detrimental accumulation of the byproducts of burning fuel, so called free radicals, or oxidative stress. We will follow horses over time, beginning during the lower-intensity early training season, so that we can identify changes early and before abnormal enzyme levels develop. This way we will be able to show if changes in metabolic pathways develop before GGT activity increases.
The second factor is a possible infection with a recently discovered virus that targets the liver and causes an inflammation of the organ, called hepatitis. Such an infection could explain why GGT increases as it has a high concentration in the liver. We could show previously that approximately 18 % of horses racing in California had high GGT concentrations. Of those horses, 3-5% were infected with one of the two equine viruses, hepacivirus and parvovirus, respectively. Although the number of horses that were found to be infected is low, the risk to have high GGT concentrations was higher in infected horses, and thus it could be a contributing factor to high GGT activity. Therefore, we think it is important to determine if liver infection with viruses could be causing the maladaptation to training syndrome.
Both questions will be answered by a study of a group of healthy Thoroughbred horses that will be blood samples over time. This will allow us to detect early on when the GGT concentration is increasing and study the changes in metabolism or viral infection that happen concurrently or before GGT increases. To do this, we will quantify over 250 different metabolites in the serum samples of healthy and high GGT horses (15 animals each), and compare the findings to find metabolic clues to understand the syndrome. We will also subject these horses to a training race to see if some of the metabolic markers that we are looking for may only be changing for a short period of time after the animals are challenged. In addition, we will detect and quantify virus particles in the blood of these horses to determine if recent virus infection is more likely in horses that develop high GGT concentrations. Our goal is to find the reason for the increase in GGT activity so that we can help identify possible strategies to prevent and treat horses that develop this syndrome.
Maladaptation to training syndrome affects the performance of equine athletes. The syndrome is defined as an imbalance between training and recovery that is associated with unexplained signs of reduced performance. The “poor performance horse” is thought to be associated with abnormalities in the results of enzyme activities in the blood of affected. No cause has been established definitively to date.
Trainers and race track veterinarians report that a persistent elevation in GGT (above 50 U/l) is associated with a decline in performance. No cause has been found although our preliminary studies suggest it may be caused by either oxidative stress or recently discovered hepatitis viral infection. Regardless of the cause, affected horses generally require several weeks of rest before the GGT returns to normal causing a decrease in starts. Additionally, the economic impact of a perceived reduction in performance in horses that may continue racing might also have severe economic consequences for the owners and perpetuate the ill health in affected horses. In many horses the onset of the disorder is in late spring or early summer which might result in loss of the remaining season and in some cases the syndrome has prevented high profile horses from running in televised stake races and disappointment to the racing public. Given the relationship of high GGT concentrations as a marker or cause of poor performance, and the striking lack of studies investigating causal or associative pathways, we believe a strategic approach is needed that will allow us to create the necessary evidence to address this problem. We aim to address this gap in knowledge and if successful, will be able to identify specific management or treatment strategies.
Equine metabolic syndrome (EMS) and EMS-associated laminitis (EMSAL; founder) are important and increasingly prevalent conditions in horses and ponies; EMSAL is the most common cause of founder in equine populations in developed nations, and it imposes a significant financial and animal welfare burden on the equine industry worldwide. Abnormalities in regulation of insulin and blood glucose (somewhat similar to that seen in pre-diabetic humans) is a hallmark of EMS and is directly involved in the risk of founder in affected animals; treatment strategies for EMS patients primarily revolve around reducing abnormalities in insulin and glucose responses to food in attempt to minimize this risk in affected horses. Currently, strategies to minimize the amount of sugar and starch in the diet (which cause increased insulin levels) and maximize regular aerobic exercise are central to this goal. However, even though many medications are available for improving insulin/glucose dynamics in humans, very few have been shown to be effective in horses; given that many affected horses are unable to participate in aerobic exercise due to the pain and debilitation of founder, treatment with drugs whose effects mimic those of aerobic exercise would be useful for managing these difficult cases. An enzyme termed 5’-Adenosine-monophosphate-activated protein kinase (AMPK) is important in humans and animals because it regulates metabolism in virtually all cells of the body and is important for sensing energy deprivation in the body; medications that activate the AMPK enzyme are a mainstay of medical treatment of metabolic syndrome and type II diabetes mellitus in human medicine. These medications promote normal blood sugar levels, burn fat, and improve insulin function in treated humans; therefore, since horses with EMS have similar metabolic problems as people with pre-diabetes, AMPK activation would also be an attractive treatment strategy for them. However, the ability of these human medications to activate the AMPK enzyme in horses is unknown. Metformin hydrochloride, a drug that activates AMPK that can be given orally, improves glucose and insulin levels in humans and is prescribed widely for this reason. Although metformin is given to horses clinically already, it has not been widely studied in this species. It is not absorbed from the GI tract in horses as well as in humans, and some investigators have suggested that it acts locally within the intestine to block absorption of sugars in feed (minimizing effects on blood sugar following meals). Recently, aspirin has also been shown to activate AMPK in people, and in contrast to metformin, aspirin is well-absorbed from the intestines in horses when given orally and has been given to horses for many years to treat inflammatory conditions. Further, aspirin and metformin have been shown act synergistically in improving insulin and glucose levels in humans; this would also be incredibly attractive for treatment of horses with EMS but hasn’t been investigated to date. Therefore, we plan to induce temporary insulin and glucose abnormalities (i.e. induce insulin dysregulation similar to pre-diabetes in human) in 14 adult horses using dexamethasone (a steroid medication used frequently to treat inflammatory and allergic diseases in horses, such as arthritis and heaves); following a 7-day induction period, 7 horses will be treated with metformin, and 7 horses will be treated with aspirin for 6 days. After this period, 7 horses will be treated with metformin and aspirin combination therapy for an additional 7 days. Blood samples, liver biopsy, and skeletal muscle biopsy samples will be collected at 1) baseline, 2) following induction of insulin and glucose abnormalities (i.e. insulin dysregulation similar to what occurs in equine metabolic syndrome), 3) following metformin or aspirin therapy, and 4) following combination therapy; these samples will be used to measure lipid and hormone concentrations and levels of tissue AMPK activation in each horse. Two tests (oral glucose test and combined insulin and glucose test) will also be performed at these same time points to evaluate the effects of the drug treatments on blood levels of insulin and glucose (and the insulin/glucose response to sugar challenge). Finally, the concentration of metformin will be measured in blood and liver samples collected from the MET treatment group to see if metformin is absorbed from the GI tract. We anticipate that the results of this project will provide valuable information about the ability of metformin and aspirin to activate the AMPK enzyme and improve abnormalities in insulin and glucose levels present during insulin dysregulation in horses and evaluate whether either or both of these medications might be suitable treatments for horses with EMS and EMSAL. Finally, we expect to clarify the likely predominant site of action of metformin (gastrointestinal tract mucosa vs. liver) in horses.
Laminitis is a crippling disease of horses and ponies that remains a major cause of morbidity and mortality worldwide. Laminitis has been identified as the most important priority for equine research by the American Association of Equine Practitioners due to both the high incidence of the disease (annual incidence of 2–7% of horses in recent studies), the severe and painful nature of the disease (horses often humanely euthanized or retired from competitive/useful activity secondary to chronic, intractable lameness), and the lack of effective therapies for treating it. In one of the largest studies of the incidence of lameness in the U.S. in recent history, a USDA National Animal Health Monitoring System study published in 2000 including data from approximately 3000 horse farms in 28 states stated that 13% of these farms reported a case of laminitis in a one year period. Of the different forms of laminitis, so-called “endocrinopathic” laminitis is by far the most common, accounting for almost 90% of laminitis cases presented to the equine general practitioner in a recent study. This form of laminitis affects adult horses of any age and breed, but, in the Thoroughbred industry, it is most common in brood mares and stallions where it is a major cause of loss of usage as well as premature death. Equine metabolic syndrome, an endocrine disease in the horse where excess nutrition and obesity lead to insulin disturbances, is the most common cause of endocrinopathic laminitis. We hypothesize that two drugs, metformin and acetylsalicylic acid (aspirin) will improve insulin and glucose dynamics in the horse with insulin dysregulation. This work may result in the establishment of an effective drug protocol for addressing insulin dysregulation-the primary component of endocrine disease in the horse that leads to laminitis.
Equine herpesvirus-1 (EHV-1) infection results in sporadic but devastating outbreaks of neurological disease in the equine population caused by a myeloencephalopathy with a poorly understood pathogenesis. The impact of EHV-1 myeloencephalopathy (EHM) on equine health and industry is highlighted by a series of major outbreaks in North America over the past decade, including the largest outbreak ever in 2011. Despite the importance of EHM, effective prevention remains elusive. This inability to protect horses from EHV-1 and neurological disease is thought to be due to the fact EHV-1 modulates host defense mechanisms and hides in the blood cells and nerve cells after initial infection where it coexists with the horse for life. Interestingly, for EHV-1, infection can be controlled by host immunity in younger individuals and EHM occurs in LT 10% of infected horses. In contrast, the incidence of EHM dramatically increases in horses GT 20 years to ~ 70%. Specific elements of the horses’ immunity are probably responsible for the increased incidence of clinical EHM in younger horses and those are likely highlighted in aged horses. We propose to use this phenomenon to our advantage and compare the immune responses in old and young horses to identify the mechanisms that lead to the virus’s “waking up” and causing neurological disease in horses. This will allow us to (1) understand how the virus stays hidden and what leads to it “waking up”, which is critical as avoiding the virus from hiding in the first place or alternatively keeping it from waking up, is the cornerstone herpesviral control long term, (2) identify factors that contribute to EHM; and (3) elucidating target points for therapeutic and preventative intervention.
EHV-1 and its devastating sequel EHM continues to cause significant disease in the affected animal as well as causing extensive economic losses through closure of race tracts and sales barns, delays in training schedules and death of valuable animals. The substantial impact of EHV-1 on equine health is highlighted by a series of major outbreaks in North America over the past decade, including the largest outbreak ever in 2011 which infected over 90 horses in 10 states, resulting in at least 13 fatalities and enormous financial costs to the equine industry. Despite years of research, major outbreaks of EHV-1 remain a worldwide problem demonstrating the limitations of current vaccination strategies in the horse. The major current limitation in our preventative efforts are that EHV-1 modulates host defense mechanisms and hides in the blood cells and nerve cells after initial infection where it coexists with its host for life. During the aging process of the horse the balance between the horse and the hidden virus shifts to where the virus starts multiplying again and the overzealous immune response to the virus causes damage in multiple parts of the body, including the spinal cord and leads to neurological disease. We propose to use this phenomenon to our advantage and compare the immune responses in old and young horses to identify the mechanisms that lead to the virus’s “waking up” and causing neurological disease in horses. Understanding how the virus hides and what causes it to “wake up” will lead to the development of therapeutics to avoid the virus from hiding in the first place or alternatively keeping it from waking up. Further, the identification of factors that contribute to EHM will elucidate target points for therapeutic and preventative intervention. Finally, some of the tools used to study differences between young and old horses might also provide new diagnostic tools that could be used in outbreak conditions to identify horses at risk for developing EHV-1.
The sequencing of the horse genome in 2009 resulted in significant advancements in the field of equine genetics. Currently, there are 41 equine traits, including genetic diseases and coat colors, for which a genetic test is available. Of these, 31 were discovered since the horse genome was made publically available. The next step forward in the study of complex equine diseases is to define gene expression (which genes are making proteins in which tissues and how much protein is being made) and gene regulation (which genes are turned “on” or “off” in each tissue). Similar to other species, the horse has approximately 21,000 genes in its genome, which make up only a very small portion of the horses’ entire 2.7 billion bases of DNA. While it is known that changes in coding DNA (i.e., DNA that creates protein) may lead to disease, what is not known is the consequence of changes in non-coding DNA (i.e. DNA between coding regions). The vast majority of the equine genome consists of this non-coding DNA, whose function remains a mystery. It is apparent, however, that non-coding regions of DNA can bind proteins that will turn a gene “on” in one tissue, lung for example, while that same gene is “off” in another tissue, such as liver. The future of equine disease discovery lies in unraveling the location and function of these important DNA sites and determining, on a tissue-specific basis, how these noncoding regions of the genome regulate gene expression. In human research investigating complex genetic disease, as many as 93% of studies attempting to link a disease with a region in the genome identify an associated region within non-coding DNA. Similarly, many complex genetic diseases in the horse map to non-coding regions of the genome. The study proposed here parallels advances in human genomics and puts equine research on the cutting edge of disease discovery. This study will provide the foundation for not only equine genetic research but also research into the function and dysfunction of many specific equine disorders from laminitis to typing-up to heaves, among many others.
For the first time, we have the available tools and expertise to unravel these DNA and protein interactions that regulate gene expression. Our goal is to provide an open-access resource, a genomic roadmap outlining the location and function of non-coding “on/off switches,” for all researchers.
With support from the Grayson Jockey Club Foundation in 2016, a tissue-specific equine biobank and database of gene expression and regulation is being built. This proposal seeks to expand upon this initial progress to determine the location of additional regulatory elements. This annotation will extend to include the location of additional modifiers of gene expression using a technique called CTCF-sequencing, and discover important regulatory regions with a technique called ATAC-sequencing. While the initial analyses are being performed on 8 tissues, we have archived GT 80 tissues from each horse that is available for future studies. In fact, this biobank has already been leveraged through an international collaboration, whereby 24 individuals representing 16 research institutions in 10 countries provided funding, totaling $44,000, for the tissue(s) most relevant to their own research for RNA-sequencing. This has maximized the initial investment from Grayson Jockey Club. All data is publically available to the entire research community. We propose that development of this roadmap is as important to the equine industry today as the sequencing of the equine genome was in 2009.
Genetic studies have been performed for many important complex diseases, including fracture risk and tying-up in Thoroughbred racehorses, recurrent airway obstruction (“heaves”), osteochondrosis dissecans (OCD), navicular disease, and recurrent uveitis (“moon blindness”), among many others. Despite the results of these studies, which have successfully identified locations in the genome that may be associated with a specific disease, functional genetic mutations have not been discovered in any genes within these regions to date. For example, a region on chromosome 13 was associated with heaves in Warmbloods, but no mutations were identified in neighboring protein-coding genes. These genetic associations may indicate that a non-coding region of the genome is contributing to development of clinical disease. Additionally, many other active areas of equine research, including laminitis, immune response to infection, reproductive health, tendon injuries, and inflammatory conditions use gene expression analyses to identify biomarkers of disease. A publically available tissue-specific reference for all DNA-protein interactions in the horse would provide evidence that these non-coding regions play an important role in gene expression. In human medicine, genetic tools are used to analyze an individual’s DNA sequence, gene expression and DNA-protein interactions, thereby focusing on disease prevention and early diagnostics. Our long-term goal is to move towards this type of personalized medicine in the horse. This would allow veterinarians to screen horses and optimize treatment recommendations for the prevention of developmental disorders as well as provide specific targeted therapies for a variety of diseases based on gene expression changes in a particular individual. In addition to unraveling disease mechanisms, the DNA-protein interactions identified in this proposal would uncover new targets for biomarkers, prevention and treatment of disease.
Racehorse injuries continue to have a negative effect on the racing and sport horse industries, especially with the widespread public display and social discussions around high-profile catastrophic injury events. The Grayson Jockey Club Research Foundation and other funding bodies have invested millions of dollars in solving this problem, and have helped to improve the understanding of such injuries. However, a key missing item in solving this problem is the development of an easy-to-use imaging device that can detect the subtle lesions that lead to injury. A device that can be used to better characterize injuries and as a surveillance technique to identify “at-risk” equine athletes is needed. The goal of this proposal is to develop a 3-dimensional imaging technique that can be used in the field for diagnosis and characterization of limb injuries in horses. It is the hope that development of such a device, with the goal of being inexpensive, easy-to-use and able to detect subtle changes within the legs of horses will lead to prevention of injury.
Specifically, Limited View 3D technology will be developed for the equine distal limb, which will be achieved by taking a minimal number of radiographs to acquire a 3-dimensional image of the leg. This type of imaging technique should be achievable in the field, and better placed as a screening tool compared to existing imaging technology. This would allow the racing and sport horse industries to be better positioned to deal with the negative image that catastrophic injury causes.
The investigators propose to first use computer simulation techniques to design the device. The co-investigators at the University of Chicago have successfully done this in the human field, and along with the clinical expertise from the investigators at CSU, a device can be constructed that can be used the veterinarian in the field. Computed tomographic (CAT scan) images of the fetlock joint from normal Thoroughbred racehorses will be used as the basic model for computational modeling. Once the computer simulation is finalized the model will be validated by imaging the fetlock joints in the laboratory and comparing the results to the model. Any computer configurations found not to be valid will be replaced with options that are sound and clinically possible. This allows for real-time development of the Limited View 3D technique.
Once the imaging configuration is determined and validated, then fetlock joints with known problems will be imaged using the Limited View 3D technique and the results compared to traditional computed tomographic images. A board-certified radiologist with expertise in equine imaging will blindly evaluate images from both Limited View 3D and computed tomography to determine the value of Limited View 3D imaging. Once optimized, the results of this study will be used to develop the software and hardware configurations needed to acquire 3-dimensional images at the point of care. At this stage, a combination of funding strategies will be used to bring the technology to the equine industry, first through the development of a prototype that will be validated and clinically optimized at CSU, and then through investment strategies and collaborations with industry partners. Investigators at CSU currently possess the relationships, regulatory insight and fundraising capacity to bring such a device to the equine market. Clinicians at CSU also possess the infrastructure and experience to provide continuing education focused around such a device.
Injury in the athletic horse continues to be a major concern to the equine industry. Not only is it the most common cause of euthanasia, early retirement and lost days of training in the racing industry, but the negative press and public perception that surrounds catastrophic injury events inflicts a negative image about the industry. The negative press and perceptions around these events will likely continue to escalate with the increased reliance of instantaneous, public communications on social media. Many sources have contributed to funding research that has investigated that causes of such injuries, and we know now that these injuries are the end stage of a chronic process. A better understanding of the changes that occur in the legs of horses prior to injury is now better understood because of this investment by the equine community. However, there is a clear gap in our ability to acquire the necessary clinical information essential to identify horses that are at risk of injury. An easy to use, low-cost 3-dimensional imaging device that can be used by the veterinarian in the field is needed within the equine industry. Development of such a device will not only allow for improved characterization of lower limb injuries in racehorses, but will help to screen horses prior to racing to better prevent injury.
The investigators propose to use established computational modeling techniques to develop such a device. Imaging techniques that display 3-dimensional information about the health of the horse’s legs can be developed with a minimal number of x-ray projections. Preliminary data by the research team has shown that nearly all of the information obtained by a computed tomographic can be obtained with the proposed technique (Limited View 3 Dimensional imaging). The unique benefit of this technique is that it can be performed with a limited number of radiographic views, making it practical to use in the field by veterinarians. Results of this study will lay the groundwork for software and hardware design of this device.
The standard treatment for pneumonia caused by the bacterium Rhodococcus equi in foals has been combination therapy using one of the macrolide antibiotics (erythromycin, clarithromycin, or azithromycin) with rifampin. In the absence of an effective vaccine, control of R. equi infections at many endemic farms relies on early detection of disease using thoracic ultrasound and initiation of treatment with a macrolide in combination with rifampin prior to development of clinical signs. This practice has considerably increased the number of foals being treated with antimicrobial agents. Recently, we have documented that mass antimicrobial treatment of all the foals with lung lesions detected by ultrasound has selected for antimicrobial resistance over time, with isolates of R. equi resistant to all macrolides and rifampin being cultured from more than 10 % of affected foals in Kentucky and from up to 40% of affected foals at some farms. Foals infected with such resistant isolates are more likely to die than foals infected with susceptible isolates. We have recently identified the genetic mechanisms of leading to antimicrobial resistance in R. equi. Our preliminary data indicate that a highly resistant strain of R. equi has been transmitted from farm to farm in Kentucky and has spread to other states as well but the true frequency of resistant isolates at horse-breeding farms and the factors associated with their presence are unknown. All the techniques and methods proposed in this application have already been optimized and are applied routinely in our laboratories. We are, therefore, in an ideal position to successfully complete the research proposed in this application. Our long-range goal is to eradicate or limit the spread of resistant isolates of R. equi. However, achievement of our long-range goal will be possible only if we have a good understanding of the epidemiology and ecology of macrolide and rifampin resistance in isolates of R. equi at horse-breeding farms. After completion of this work, we will have determined: 1- how widespread are isolates of R. equi resistant to macrolides, rifampin, or both at horse breeding farm in Kentucky; 2- whether the proportion of isolates of R. equi resistant to macrolides, rifampin or both varies by sample type (soil vs air), location (stall vs paddock) and month; 3- whether the rate of detection of isolates of R. equi resistant to macrolides, rifampin or both in the environment of farms that rely on early detection of disease using thoracic ultrasound is different to that of farms that do not use ultrasound for early detection; and 4- whether resistant isolates of R. equi currently detected at farms in Kentucky still represent dissemination of the same strain or if resistance is spreading to other isolates. These are the first important steps in understanding the ecology and epidemiology of macrolide-resistance on horse farms and in developing strategies to prevent antimicrobial resistance.
Pneumonia is the leading cause of disease and death in foals in Texas and ranks 3rd as a cause of morbidity and 2nd (after a combined category of trauma, injury, and wounds) as a cause of mortality in the United States. Given the importance of infectious diseases for the equine industry, our ability to curtail antimicrobial resistance is of pressing importance. Although many microorganisms cause respiratory disease in foals, R. equi is considered the most common cause of severe pneumonia, and is important to the equine industry for the following reasons. The disease is extremely common at many horse-breeding farms with sometimes 20% to 40% of the foal crop being affected. At those farms, the costs resulting from veterinary care, long-term therapy, and mortality of some foals are very high. In addition to significant immediate costs, R. equi pneumonia has a long-term detrimental effect on the equine industry because foals that recover from the disease are less likely to race as adults. For decades, the standard treatment for R. equi foal pneumonia has been combination therapy using one of the macrolide antibiotics (erythromycin, clarithromycin, or azithromycin) with the antibiotic rifampin; effective alternatives to this combination are lacking. These antimicrobial agents are classified as critically important for human medicine by the World Health Organization. Widespread resistance to these 2 classes of drugs in R. equi isolates has become a major problem facing the horse-breeding industry and might adversely impact human health. The work proposed in this application represents the first important steps in understanding the ecology and epidemiology of antimicrobial resistance on horse farms and in developing strategies to prevent antimicrobial resistance.
There are three Career Development Awards offered through the Foundation in 2019.
The Storm Cat Career Development Award, inaugurated in 2006, is a $15,000 grant designed as an early boost to an individual considering a career in equine research. It has been underwritten annually by Mrs. Lucy Young Hamilton, a Grayson-Jockey Club Research Foundation board member whose family stood the retired champion stallion Storm Cat at Overbrook Farm.
This year there are two award winners:
“In my opinion, Dr. Stewart is the quintessential candidate for the Storm Cat Award. She is on a career trajectory that embodies academic commitment through research, clinical service and teaching. It is Dr. Stewart’s desire to pursue a career in academia following completion of her graduate work around the use and applications of computed tomography and magnetic resonance imaging to detect and explore the maladaptive remodeling changes of equine bone. I am using both institutional graduate student funds and research salary support in supporting Dr. Stewart as I believe she will develop into a highly productive clinician scientist with eventual independence.”Faculty supervisor: Chris E. Kawcak, Professor and Director of Equine Clinical Services
“In my opinion, Dr. Pezzanite is the quintessential candidate for a Career Development Award. She is on a career trajectory that embodies academic commitment through research, clinical service and teaching. As you can see from her CV she comes with a long track record of scientific recognition through awards and important publications. She has what it takes in tenacity and intellect to be a successful scientist. It is Dr. Pezzanite’s desire to pursue a career in academia following completion of her surgical residency and PhD. She will have a unique opportunity to be co-mentored between myself and Dr. Steve Dow in pursuing impactful answers to important questions regarding use of equine MSCs to improve multidrug resistant orthopedic infections. Dr. Dow is a talented immunologist that has been investigating the antimicrobial properties of MSCs in lab animal models and, most recently, dogs. He currently has an ongoing clinical trial in dogs that is revealing very promising results in animals with MDR bacterial infections. The collaboration between Dr. Dow and myself has been ongoing for several years now and we are both committed to mentoring Dr. Pezzanite. Dr. Pezzanite would be the second PhD candidate we have co-mentored (Dr. Aimee Colbath was the first and also a Career Development Awardee). Our collaborations have led to important translational observations and we share similar philosophies in mentoring graduate students. I am committing the institutional support in supporting Dr. Pezzanite as I believe she will develop into a highly productive clinician scientist with eventual independence. I therefore enthusiastically support Dr. Pezzanite’s application for a Career Development Award.”Faculty supervisor: Laure Goodrich, Professor Equine Surgery
“As an equine veterinarian and researcher, I have been blessed to work with many talented and hard-working students. Sian is at the top of this list. Sian is hard working, intelligent and dedicated. She has always gone above and beyond in research, and to maximize her learning. I believe she has the potential to be an excellent clinician-scientist, just as she has become an excellent internist. She is highly deserving of this recognition by the Grayson-Jockey Club Research Foundation.”Faculty supervisor: Molly McCue, Professor and Interim Associate Dean of Research