Bioelectronic medicine for horses, a booming high-tech field


File picture.

Equine researchers at Britain’s Royal Veterinary College (RVC) are working in the burgeoning therapeutic area of ​​bioelectronic medicine, or electroceuticals, as an alternative to medication.

Biomedical devices are used electrically to block, record, or stimulate neural activity, and have been used for some time to help improve the lives of disabled and ill human patients.

There are many existing and potential impacts of this research, spanning diagnosis, monitoring and treatments, for veterinary patients as well as humans. One example is the portable glucometer, which allows diabetic patients to measure – and therefore better control – their blood sugar levels. In neurology, electrical stimulation is used to treat patients with Parkinson’s disease, epilepsy and essential tremor. Bioelectronics has even allowed the blind to see.

In patients with debilitating conditions such as arthritis, vagus nerve stimulation (VNS) is used to activate the cholinergic anti-inflammatory pathway in the vagus nerve, resulting in a reduction in inflammation.

In species such as horses, which are extremely sensitive to drugs, pharmaceutical and surgical interventions carry risks and are not always as effective as hoped, but rapid advances in medical technology are making it possible to dramatically improve treatments and diagnostic tools available.

Researchers from the Musculoskeletal Biology group in the Department of Comparative Physiology and Clinical Sciences (CPCS) are working on the RVC’s bioelectronics project, as part of the college’s structure and motion laboratory. It is led by professor of equine surgery Justin Perkins, holder of the RCVS certificate in equine surgery (soft tissues), the ECVS diploma in large animal surgery and a European specialist in large animal surgery.

A prime target for bioelectronics is the cervical vagus nerve, which innervates various visceral organs and muscles, including the pharynx, larynx, heart, lungs, and gastrointestinal tract.

In equine veterinary practice, recurrent laryngeal neuropathy (RLN) is commonly observed. The term “laryngeal paralysis” is sometimes used, but recurrent laryngeal neuropathy is a more accurate term because immobility on both sides of the larynx is not present. As nerve function declines, the muscles that open the larynx begin to weaken, causing the airways to narrow. This results in sounds being emitted, ranging from a hiss to a roar or a gasping sound, especially at high speeds. Since the air supply can be affected, horses often perform poorly when exercised.

The most commonly used existing treatment aims to restore the diameter of the airways by “tightening” the larynx into the open position during surgery. But the success rate is only around 50% and many horses develop complications including chronic lower respiratory disease (as their swallowing is affected) or the operation fails and has to be repeated. These complications can end the career of competition horses.

Significant advances in treatment have involved electrical stimulation of the affected muscle in the larynx. Functional Electrical Stimulation (FES) is used to directly stimulate the weakened muscle to contract more strongly, both when electrically stimulated, but also with normal nerve stimulation.

In particular, the goal of FES is to produce a contraction that mimics a natural muscle contraction, without the need for the “binding” procedure, so that horses retain the ability to swallow effectively (thereby preventing tract disease). lower respiratory tract). There have been significant improvements in FES technology over the past decade, including the miniaturization of implants. Eight weeks of stimulation in a fully denervated muscle has been shown to halt muscle atrophy and increase muscle fiber diameter.


Functional Electrical Stimulation Following Nerve Injury in Large Animal ModeI, Muscles and nerves (2019)
Functional electrical stimulation leads to an increase in the volume of aged thyroarytenoid muscle, The Laryngoscope (2018)
Reverse age-related changes in laryngeal muscles by chronic electrostimulation of the recurrent laryngeal nerve, PLoS One (2016)


About Author

Comments are closed.