Free tendon research articles from the EVJ

  

Horse with acute injury to left fore
superficial digital flexor tendon.
(Roger Smith) 

Horses are unfortunately prone to tendon and ligament injuries in the lower limb, and finding a universal treatment remains elusive. Nevertheless, significant scientific progress has been made in this area.

 

In the new virtual issue of the Equine Veterinary Journal (EVJ), guest editor Roger Smith has chosen 13 articles on the subject. 

 

There have been major advances in tendon and ligament disease research during the past 30 years. The 13 papers published in this new EVJ collection have been selected from the past five years to show progress in three key areas: pathophysiology – understanding why injuries occur and how they heal; progress in regenerative medicine; uncommon tendon and ligament injuries.

 

Tendon and ligament disease of the distal limb and the factors affecting treatment are complex, with variation in the severity of injury and variability in outcome between similarly affected horses. Understanding of the pathogenesis and improved diagnostic and predictive tools should enable the development of more effective treatments in the future.

 

• Microdamage in the equine superficial digital flexor tendon provides a review of what is currently known about tendon pathophysiology as well as the effect of ageing and the response to injury.
• Modelling the effect of race surface and racehorse limb parameters on in silico fetlock motion and propensity for injury provides further evidence of how mechanical loading can adversely influence the palmar tendons and ligaments.
• Ultrasound tissue characterisation of the superficial digital flexor tendons in juvenile Thoroughbred racehorses during early race training suggests that there are short-term changes with the onset of training, although it is not possible to know, at this stage, whether these changes have any relationship to the risk of injury.
• The use of sonoelastography to assess the recovery of stiffness after equine superficial digital flexor tendon injuries: A preliminary prospective longitudinal study of the healing process. This study potentially presents another way to monitor tendon healing and predict outcomes.
• Ultrasonographic-based predictive factors influencing successful return to racing after superficial digital flexor tendon injuries in flat racehorses: A retrospective cohort study in 469 Thoroughbred racehorses in Hong Kong: This work confirms that lesion size was predictive of outcome.
• Effect of circadian rhythm, age, training and acute lameness on serum concentrations of cartilage oligomeric matrix protein (COMP) neo-epitope in horses. This study provides important information to establish a clinically useful blood assay for tendon and ligament injury in the future.
• Retrospective analysis of local injection site adverse reactions associated with 230 allogenic administrations of bone marrow-derived mesenchymal stem cells in 164 horses. This work reports the highest frequency of reactions for synovial cavities and the injection of collateral ligaments of the distal interphalangeal joint.
• Ultrasound-guided injection of the cranial tibial artery for stem cell administration in horses reports an alternative delivery of stem cells via the cranial tibial artery to hindlimb structures where intralesional treatment is not possible.
• Extracellular vesicles from equine mesenchymal stem cells decrease inflammation markers in chondrocytes in vitro investigates how MSCs potentially act.
• Retrospective analysis of oblique and straight distal sesamoidean ligament desmitis in 52 horses includes a technique for optimising ultrasonography for imaging oblique DSL injuries.
• Magnetic resonance imaging and histopathological evaluation of equine oblique sesamoidean ligaments raises the question of whether many of these ligament injuries are being missed in practice.
• Magnetic resonance imaging following regional limb perfusion of gadolinium contrast medium in 26 horses considers how this method may enhance the identification of pathology within the foot.
• Chondrosesamoidean ligament enthesopathy: Prevalence and findings in a population of lame horses imaged with positron emission tomography. This study looks at how this new diagnostic technique may identify a new soft tissue injury within the foot.

 

“The field of tendon research is generating a healthy amount of quality research to counter the commonly held belief that there is nothing better than a double helping of God and time,” said Roger Smith. “Bit by bit we are moving closer to the holy grail of ideally preventing, or successfully treating, these injuries.”

 

“This collection provides an essential educational insight into the significant progress that has been made in tendon and ligament disease research over the past five years,” said Professor Celia Marr, Editor of the EVJ. “By giving veterinary practitioners the opportunity to understand the science and the variables behind why a specific treatment may work is a fundamental step towards the ultimate goal of reliable treatment success.” 

 

The virtual issue can be found at 

https://onlinelibrary.wiley.com/doi/toc/10.1001/(ISSN)2042-3306.tendoninjury 

and will be free to view until 27 February 2024.

Research highlights limitations of non-contact infrared thermometers

According to a recent study conducted by the Department of Large Animal Clinical Sciences at Texas A&M University in College Station, TX, non-contact infrared thermometers may not serve as a viable alternative to rectal thermometry for detecting fever in horses.

 Body temperature is a crucial vital sign used for assessing health and is important for monitoring horse health and implementing biosecurity measures within groups of horses. While rectal temperature remains the gold standard for accuracy, its use can be met with resistance from horses, posing potential danger for the operator.

 

Non-contact infrared thermometers have been considered as an alternative, providing quick and convenient temperature readings without direct contact. However, these thermometers offer a rapid assessment of surface temperature, and their readings may not closely reflect the core body temperature compared to rectal thermometers. Environmental conditions and the presence of a thick hair coat can further influence their accuracy.

 

The research, conducted by Leslie Easterwood and Noah D. Cohen from the Department of Large Animal Clinical Sciences at Texas A&M University, involved a comparison of rectal temperatures with recordings obtained using a non-contact infrared thermometer in 142 Quarter Horse horses and 34 Quarter Horse foals. Measurements from the non-contact infrared thermometer were collected from the forehead or neck, while rectal temperatures were recorded separately for each horse and foal.

 

The study revealed that the readings obtained by the non-contact infrared thermometer demonstrated good reliability in terms of measurement repeatability. However, these readings did not align well with rectal temperatures. Notably, there was a substantial negative bias, with adult horses displaying non-contact infrared thermometer readings nearly 2°F lower than rectal temperatures. This difference was more pronounced in foals, where the average difference exceeded 3°F.

 

In conclusion, the researchers assert that the substantial and inconsistent bias observed with the non-contact infrared thermometer indicates that these devices may not be a suitable substitute for rectal thermometry when aiming to obtain valid estimates of core body temperature in horses.

 

 

For more details see:

Agreement of Temperatures Measured Using a Non-Contact Infrared Thermometer With a Rectal Digital Thermometer in Horses,

Leslie Easterwood, Noah D. Cohen

Journal of Equine Veterinary Science,(2023) Vol 123,104243,

https://doi.org/10.1016/j.jevs.2023.104243

Effect of different hay feeders on behaviour

 Horses, being continuous grazers, have a natural inclination to feed steadily. Feral and wild horses may spend about 16 hours per day grazing. 

Allowing domesticated horses free access to roughage aligns with their natural feeding behaviour, representing a potentially optimal approach for horse health and welfare.

However, there are instances where restricting their food intake becomes necessary for management or health reasons. Nevertheless, such restrictions may impact their welfare and behaviour.

 

Implementing tools like hay-nets/bags and slow-feeders may prove helpful in decreasing food waste, extending the time horses spend consuming roughage, and potentially reducing undesirable behaviours.

 

The introduction of automatic hay boxes, providing scheduled feeding times throughout the day, contributes to minimising food waste. Despite this advantage, timed feeding through these devices may lead to abnormal behaviours in horses due to limited access to roughage.

 

A recent study evaluated the impact of three different hay feeders and the availability of roughage on horse behaviours in dry feed lots. The goal was to identify improved feeding techniques that could optimize feeding management, diminish abnormal behaviours, and improve the overall welfare conditions of horses in equine establishments.

 

Fifteen healthy thoroughbred cross horses from the Polo Club at Colorado State University participated in the research, employing a 3x3 Latin square design. The study comprised three groups, each consisting of five horses, with each group undergoing 15 days of one of the three treatments: free choice hay, slow feeder, or box feeder. At the conclusion of each treatment period, the horses underwent weighing, and blood samples were collected to monitor cortisol levels. Behaviour was  monitored throughout the final day of each treatment session.

 

The research, funded by Morris Animal Foundation, is published in Journal of Equine Veterinary Science.

 

Lead author, Jéssica Carvalho Seabra, said “Taking care of horses means more than just giving them a place to stay, food and water. It means giving them an environment where they can do things that are part of their natural behaviour like grazing.”

 

The researchers found that horses using automatic boxes and slow feeders consumed less and exhibited slower weight gain, indicating effective regulation of food intake. 

 

Horses with the freedom to choose when to eat had the highest hay utilization and weight gain rates, suggesting that this approach might not be optimal for overweight horses.

Horses with access to free choice feeding or a slow feeder spent more than half their day doing natural activities such as foraging. 

 

In contrast, horses using box feeders spent only about a quarter of their day eating, leading to increased time spent standing, sniffing the ground, and consuming their own faeces.

Furthermore, horses using the box feeder displayed more signs of aggression. During the study, the researchers noticed that horses became more aggressive as the feeders' size decreased and access to the food became more difficult. To address this issue, researchers recommend ensuring adequate space for each horse to eat without feeling crowded, especially when providing a limited amount of food.

 

"Selecting the right feeding technique can extend the time horses engage in natural behaviours, reducing the incidence of chronic stress and potentially curbing the emergence of abnormal and stereotypic behaviours in the long run," Carvalho Seabra said.

 

For more details, see:

 

Jéssica Carvalho Seabra, Tanja Hess, Marcos Martinez do Vale, Katherinne Maria Spercoski, Ryan Brooks, João Ricardo Dittrich,

Effects of Different Hay Feeders, Availability of Roughage on Abnormal Behaviors and Cortisol Circadian Rhythm in Horses Kept in Dry Lots,

Journal of Equine Veterinary Science (2023) Vol 130, 104911,

https://doi.org/10.1016/j.jevs.2023.104911.

Prevalence of laminitis in Norwegian ponies

New research highlights the problem of laminitis in the Norwegian Nordlandshest/Lyngshest pony breed.

Ponies, in general, are prone to laminitis and field observations suggest Norwegian breeds are no exception

 A recent study by Sigrid Lykkjen, Ingrid Hunter Holmøy from the Faculty of Veterinary Medicine at the Norwegian University of Life Sciences, and Linda Koldal Stenbakk from the Forus Hesteklinikk, sheds light on the prevalence and risk factors associated with laminitis within this pony breed. A full report of the study is published in Acta Veterinaria Scandinavica

 

The Nordland or Lyngshest, native to Norway, is typically small to medium-sized, standing at 12 to 14 hands (48 to 56 inches or 122 to 142 cm) at the withers. With a compact and muscular build, these ponies are well-suited for tasks in challenging mountainous terrains, commonly employed in riding, driving, and therapeutic riding programs.

 

The study aimed to assess the prevalence and risk factors for laminitis in the Norwegian Nordlandshest/Lyngshest pony breed. To address the question, the research team used questionnaires distributed among members of the Norwegian Nordlandshest/Lyngshest breed association..

 

Analysis revealed age, sex, and regional adiposity as notable risk factors for laminitis. Moreover, the level of exercise and outdoor housing was significantly correlated with a reduced prevalence of laminitis.

 

For horses over nine years old, the lifetime prevalence of laminitis approached 20%. However, the overall lifetime prevalence across the entire population was comparatively lower. The researchers attributed this lower prevalence to the study's inclusion of a substantial number of young animals (24% aged five years or less), suggesting their contribution to the overall lower incidence of laminitis.

 

In conclusion, the researchers emphasize that laminitis poses a considerable welfare challenge within the Nordlandshest/Lyngshest pony breed.

 

“The identified risk factors, namely age, sex, and regional adiposity, underscore the importance of heightened diagnosis and monitoring of EMS/insulin dysregulation in the breed. Additionally, the findings highlight the necessity for enhanced owner education and awareness of strategies aimed at reducing the risk of laminitis.”

 

For more details, see:

 

Prevalence and risk factors for laminitis within the Norwegian pony breed Nordlandshest/Lyngshest

Sigrid Lykkjen, Linda Koldal Stenbakk & Ingrid Hunter Holmøy 

Acta Veterinaria Scandinavica (2023) vol 65, Article number: 22