By: Nicole Kitchener
Updates on equine research across Canada from stem cells, sudden-death syndrome, proud flesh and other pertinent racehorse ailments
Canada is a major player on the equine research scene with our five faculties of veterinary medicine undertaking a vast range of health, behaviour and management research programs. This work boasts significant impacts, not only within the horse industry itself, but also on the health and welfare of other species, including humans.
Canadian Thoroughbred looks at samples of groundbreaking equine research from each of our country’s veterinary schools.
University of Prince Edward Island, Atlantic Veterinary College
Overall, UPEI’s research income rose from $3 million a decade ago to $16 million in 2009 – a 430 per cent increase – making it the number one school for funding growth during that period. The AVC, currently celebrating its 25th anniversary year, is undergoing a $45 million capital expansion.
Stem Cell Research
Dr. Laurie McDuffee, associate professor in large animal surgery at the Atlantic Veterinary College, continues research into cell-based tissue therapy in which stem cells are extracted from an injured horse’s healthy tissue, multiplied in the laboratory and re-injected into injured tendons and ligaments and bones to aid healing and reduce the chance of re-injury. Although the work currently focuses on healing high-performance horses, it may also lead to human applications.
In early 2008, AVC struck a partnership with UK-based VetCell Bioscience Ltd, establishing the university as a Canadian centre to introduce VetCell’s equine stem cell therapy technology, which is currently being used in several other countries. In 2009, the Atlantic Canada Opportunities Agency’s Atlantic Innovation Fund – which encourages commercialization of research in the region – announced an impressive $2.1 million in funding for the project over a four-year period.
“With this research funding, the lab team has been able to go further with the equine bone healing research and move into companion animal stem cell research,” says Dr. McDuffee.
Joint Disease Diagnosis
Joint disease and injury commonly results in osteoarthritis. This painful and disabling condition usually requires medication, often for life. Early diagnosis and treatment could help prevent or minimize the effects of osteoarthritis.
Infrared spectroscopy is a technology used to evaluate biological fluids, including joint fluid. Essentially it involves shining a light through the liquid and using a sensor to see which wavelengths of light pass through the liquid and which wavelengths are absorbed. This allows researchers to identify the exact chemical composition of the solution.
Led by Dr. Chris Riley, researchers at AVC have developed a new spectroscopic technique called “multivariate infrared Fourier transform spectroscopy” to examine joint disease in the horse.
Riley and his team used infrared light to determine the types of chemical bonds in joint fluid and blood serum allowing them to detect an osteoarthritis “fingerprint” in horses. The ultimate aim of the research is to provide fast and inexpensive diagnosis to facilitate treatment before osteoarthritis sets in.
Applications using this relatively inexpensive and common technology are also being developed for lameness in dogs and immune function in newborn humans. The technology is also being adapted for use in developing quick and inexpensive tests for: failure of transfer of passive immunity in foals and humans; osteochondrosis and traumatic arthritis in horses; and immunity and antibody production.
University of Guelph, Ontario Veterinary College
The OVC, which celebrates its 150th year in 2012, is undergoing a multi-year expansion. Part of this growth includes the eventual construction of a new Equine Sports Medicine and Reproduction Centre. Currently, more than 20 individual equine projects are ongoing in which OVC faculty are lead researchers. In 2010, the E.P. Taylor Equine Research Fund announced a funding boost of $2 million toward research into the health and performance of racehorses.
Studying Pregnancy Signals
Of the pregnancies diagnosed by ultrasound about two weeks after breeding mares, approximately 16 per cent subsequently fail and about 60 per cent of those failures occur within the first five weeks of pregnancy.
During the third week, the embryo, enclosed in a capsule, at- injection of taches to the endometrium (uterine lining) where the placenta will develop. However, often, pregnancy does not progress successfully from this point.
Veterinary researcher Dr. Keith Betteridge and collaborators are investigating why this occurs. Previous studies identified that the embryo exchanges signals with the mare via chemical signals. If the signals aren’t in synch, the pregnancy is lost. “As in life,” says Dr. Betteridge, “communication is critical!”
Current research involves collecting embryos and endometrium from normal and “failing” pregnancies to investigate changes in proteins, steroid hormones and other molecules that will determine a pregnancy’s success. Anticipated results are the eventual development of diagnostic tests to find out whether a mare is likely to have a full-term pregnancy as well as development of new infertility treatments.
Sudden Death in Thoroughbred Racehorses
Dr. Peter Physick-Sheard is investigating possible causes of sudden cardiac death (SCD) in racehorses and other competition horses. Although it’s assumed the primary cause is often a disturbance in heart rhythm (arrhythmia), post-mortems are inconclusive and real-world data to prove or disprove this assumption has been non-existent to this point.
Physick-Sheard’s research is intended to analyze the normal range of rhythm variations, to help develop strategies to minimize risk of SCD and, perhaps even provide valuable information for training.
In 2007, Physick-Sheard and his team of researchers began studying the heart rhythm of standardbred racehorses from harnessing until the end of the race using a portable and non-interfering electrocardiogram (ECG) monitoring device. They discovered disturbances in rhythm immediately after the race that could possibly be a factor in SCD.
Because SCD is more prevalent in thoroughbred racehorses than in standardbreds, they began studying horses at Woodbine in late 2010 (read more in Canadian Thoroughbred Sire Book/ Dec./Jan. 2010). Physick-Sheard will return in the summer of this year to gauge the effects of environmental factors such as temperature and humidity on heart rhythm.
“Data of this type have never been collected during live racing before, so we have no idea what we might ultimately find. One thing we have discovered, however, is a very welcoming and helpful backstretch community without whose engagement we could certainly not have contemplated a study such as this,” said Physick-Sheard.
University of Saskatchewan, Western College of Veterinary Medicine
In the mid-1970s, the WCVM’s Equine Health Research Fund (EHRF) and its research fellowship program were established. In February, construction begins on an expansion to the horse health centre that will add 11,000 square feet and resources for teaching, clinical work and research. The expansion will be called the Ryan/Dube Equine Performance Centre, honouring the couple that donated $1.2 million toward its construction. The province, Spruce Meadows’ Marg and Ron Southern and the WCVM provided the remaining funding for the $2.8 million project (read more in this issue, page 16).
Battling a Bacterial Menace
A team of researchers is investigating Rhodoccus equi (R. Equi) infection, the leading cause of pneumonia in foals between three weeks and five months old. The pneumonia generally remains undetected until it is well advanced and is often fatal. A foal’s immune response during those first few weeks and months is often not strong enough to fight foreign cells such as R. Equi, a soil-borne bacterium. Management of the disease depends on early diagnosis, which is time-consuming and expensive, Townsend has said.
Studies led by Dr. Hugh Townsend examine foals from the time of infection, allowing researchers to find out when the disease is detectable, what the immune responses are and individual foal’s genetic variations affecting immunity.
A key objective is to create vaccines that can be given to foals under the age of five months, which would be of great value for use against R. equi, as well as other diseases and may also have applications in the health of other young animal species and humans.
Ulcers in Performance Horses
Dr. Fernando J. Marqués, a specialist in large animal internal medicine at WCVM, recently completed a study that looked into the prevalence of equine gastric ulcer syndrome (EGUS), more specifically nonglandular squamous disease, among western Canadian horses, particularly performance animals.
Previous studies from around the world had already confirmed thoroughbred racehorses are most affected by nonglandular squamous disease, but Marqués and his research team wanted to find out if Saskatchewan horses, who only race three months of the year and are pastured in the months leading up to racing, would be similarly affected. Turns out, they are.
Using a three-metre gastroscope, portable digital recording and imaging system Marqués and his research team examined thoroughbred racehorses at Saskatoon’s Marquis Downs during the 2008 and 2009 racing seasons. The team discovered 74.5 per cent of the 94 racehorses involved in the study had stomach ulcers.
A follow-up study will use these results to establish if there’s a relationship between cortisol concentration in the hair and ulcers. A link between the so-called “stress hormone” and stress levels has been indicated in previous studies of wild animals.
“If we consider that cortisol increases with stress due to pain, then horses with severe gastric ulceration, and presumably in pain, may have higher cortisol levels than horses with no gastric lesions,” explains Dr. Marqués. This could lead to screening tests that would help owners and veterinarians make treatment and management decisions to prevent and/or mitigate the effects of stress and ulcers.
University of Montreal, Faculty of Veterinary Medicine
The Faculty of Veterinary Medicine in Saint-Hyacinthe celebrates its 125th year in 2011. Of the many equine-related research projects that are ongoing, the equine research group, established in 1982, focuses on clinically oriented research mainly in the areas of the respiratory and musculoskeletal systems.
Inside Proud Flesh
Granulation tissue, a normal component of wound healing, is composed of new blood vessels and cells migrating from the surrounding skin. It serves as a scaffold for skin to grow over and scarring to occur. “For some unknown reason,” says Dr. Christine Theoret, professor and equine surgeon, “in limb wounds, the granulation tissue sometimes becomes exuberant.” This is better known as proud flesh.
Theoret is investigating ways to artificially manipulate the levels of certain genes and proteins in leg wounds so that healing can occur in a manner similar to body wounds, which generally heal without problem.
It has been theorized that tissue hypoxia (lack of oxygen) is a contributing factor in the development of proud flesh. Theoret’s soon-to-be-published study provided evidence of hypoxia in limb wounds during the early period of the repair process and a more prolonged oxygen demand during the late period of healing. Further studies should prove greater hypoxia in wounds developing proud flesh. This will provide a basis to develop appropriate treatments.
Dr. Theoret is also looking into the use of anti-cancer drugs to help slow blood vessel growth – an important component of proud flesh. The work is relevant to human medicine, too, as proud flesh is similar to keloids (overscarring) in humans. No other species has been discovered to suffer naturally from keloids, so the horse may be the perfect model for research.
Dr. Jean-Pierre Lavoie, professor in Equine Internal Medicine, and a multi-disciplinary team, is researching whether structural changes – known as “remodelling” in the airways of horses with heaves (recurrent airway obstruction or RAO) are reversible by removing environmental allergens or by using anti-inflammatory drugs.
In heaves, when an environmental allergen is inhaled, the immune system responds by producing chronic inflammation in the airways, leading to alterations of the lung tissues due to damage and repair processes within the lung tissue.
Lavoie and his colleagues examined horses’ lung tissue samples before and during bouts of heaves and after a course of drug treatment with a synthetic corticosteroid. “We have confirmed that horses with heaves have approximately twice as much smooth muscle surrounding their smallest airways,” says Lavoie, adding that they also found an increase of collagen (found in scar tissue) in the airways of these horses.
Furthermore, preliminary results indicate that treatment for 11 months with inhaled corticosteroids or improvement in the environment, while controlling the clinical signs at rest, only partially decrease the airway smooth muscle.
“We believe that these results are very important as they indicate the need to develop early markers of the disease that would allow us to intervene early, before susceptible horses develop the lung lesions observed in heaves,” says Lavoie.
Human asthma sufferers and horses with heaves share similar disease characteristics. “We hope that our findings will contribute to improve both human and equine health,” says Lavoie.
University of Calgary, Faculty of Veterinary Medicine
The government of Alberta decided to launch a faculty of veterinary medicine at the University of Calgary in 2004. The faculty opened in September 2008, offering DVM, graduate, undergraduate and research programs. One of the UCVM’s major areas of emphasis in teaching and research is equine health.
A View Inside
Dr. Renaud Leguillette is an equine internal medicine specialist with interests in chronic respiratory disease in horses and biology of airway smooth muscle in horses and humans. Leguilette, who heads the faculty’s Equine Respiratory Laboratory, secured a special tool in the research and diagnosis of respiratory disease.
Calgary is the first veterinary faculty to own a dynamic respiratory scope (DRS) – a portable, wireless endoscope that allows clinicians and researchers to see inside a horse’s upper airway while the horse is at work or exercising.
Traditional endoscopy is limiting. Often a condition such as respiratory noise or decrease in performance doesn’t appear until the horse is exercised. Previously, a high-speed treadmill was required to observe the upper airways during exercise, which sometimes required horses to become accustomed the machine, potentially risking the safety of the animal and personnel.
The DRS enables the horses to be worked in their normal workout environment. The rider wears a backpack or it is attached to a sulky or cart and it is then attached to the horse. The backpack transmits video of the horse’s airway. Those images can be recorded and played back, allowing for diagnosis of upper airway problems.
Among Leguillette’s other studies are investigations into inhaled medications in the treatment of equine inflammatory airway disease (read more about the DRS in Canadian Thoroughbred, April 2010).