Did you know horses can swim? QF research explores it as an equine rehabilitation tool

Horses have a natural instinct to swim; their huge lungs act like built-in floatation devices. But, just like humans, some are better than others. While it may seem so now, horses are not new to swimming. In the past, wild horses migrated from one place to another in search of green pastures, often involving swimming across water bodies, making it a necessary means of survival.

“Swimming is immensely beneficial for improving fitness, endurance, stamina, and flexibility among horses. The natural resistance of water pushes the horse to work harder, resulting in toning their muscles and increasing their heart and lung capacity,” said Dr. Florent David, Senior Equine Surgeon at Qatar Foundation’s (QF) Equine Veterinary Medical Center (EVMC).

Dr. David’s father was an ambulatory veterinarian, which meant animals were a big part of his life growing up. Before becoming a vet, Dr. David was an avid horse rider and won the national showjumping championship for young horses in France in 1994.

Dr. David initially trained to become a horse surgeon but realized that while surgery is the best option in some cases, in others it just isn’t the answer or isn’t practical. “When you deal with athletes in the middle of a season, you cannot stop the horse and do a surgery, it doesn't fit with their competition schedule. So, I started to think differently, then I trained to become a specialist in Sports Medicine and Rehabilitation,” said Dr. David.

In the past few years, swimming has attracted increasing attention as a conditioning and rehabilitation tool for horses. However, the lack of evidence-based studies reporting on the physiological benefits of horses makes it challenging to incorporate swimming exercises into training programs.

In an attempt to bridge this gap, Dr. David’s group, in collaboration with Prof. Renaud Leguillette from the University of Calgary, Alberta, Canada, have been carrying out an in-depth study to describe the various motions horses undergo while swimming and their benefits.

“We placed markers on the skin around their limbs and used underwater cameras to record their limb and back movements. Using a specific piece of software, we were then able to analyze the kinematics during the motions in very fine detail, allowing us to report on the swimming style, speed, and degree of flexion of different joints in the front and hind limbs.”

Speaking on why swimming is a favorable rehabilitation technique for horses, Dr. David said: “Swimming is an intense but low-impact exercise activity that doesn’t put any unnecessary strain on the existing injuries, making it an effective form of rehabilitation.”

According to Dr. David, swimming is particularly attractive for the rehabilitation of tendon and suspensory ligament injuries. Tendons act like springs in the body, absorbing force placed on the bones during movement. As a result, tendons and ligaments typically carry a lot of the horse’s weight and are much more prone to injury than other areas of the body.

In horses with tendon and ligament injuries, swimming allows them to return to some form of exercise and maintain muscle and cardiorespiratory fitness without putting pressure on the injury.

While not studied in detail yet, Dr. David’s initial observations indicate swimming could also possibly help speed up fracture healing.

“One of the issues we face with horses is that they love being active and, unlike humans, don’t necessarily understand that they need to rest post-fracture repair. As soon as they feel good, they want to start running around, resulting in drastic stress rise on the limb that has just been repaired, which puts them at a high risk of re-injuries.”

In Dr. David’s opinion, swimming provides the perfect alternative, instead of trying to force the horses to rest as traditionally done. It provides a safe way to help them burn energy while minimizing stress on the recovering limb.

The acceleration of the fracture healing process through swimming could also be related to the increased heart rate during swimming, which results in higher blood flow to the limb and indirectly to the injured area hence speeding up the healing process.

He said: “In normal conditions that involve extended resting periods post-fracture repair surgery, we tend to see the fracture line disappear after three months. With swimming, we've been able to see the fracture line disappearing after a month and a half, indicating advanced bone healing. This is cutting the recovery time by half, which is always appreciated in the life of an athlete.”

To support his observations, an axis of research the team will be investigating in the future is whether swimming can speed up bone healing.

Dr. David’s research findings were presented at the 2021 annual American College of Veterinary Sports Medicine and Rehabilitation (ACVSMR) conference and were awarded first place.

Prof. Leguillette said: “This study has been an important first step towards filling a large gap in equine rehabilitation methods. By describing the underwater cycle of motion of front and hind limbs for the first time, we hope this study will help improve the scholarly community’s understanding of how swimming can be used in a more effective and targeted way thereby assisting in the development of evidence-based swimming protocols.”

The next step in Dr. David’s Sports Medicine and Rehabilitation research is to measure the amount of stress on tendons and suspensory ligaments during high-intensity activities – like jumping, endurance, or flat racing – and compare them with the stress associated with swimming. The research group will then aim to design swimming protocols to train horses differently, reducing the burden of injuries in those areas.