Charcoal Could Help Horses At Risk for Atypical Myopathy
There’s a potential new weapon in the fight against the fatal muscle disease atypical myopathy: charcoal.

Activated (oxygenated) charcoal sent through a nasal tube into affected horses’ stomachs might help stop the intoxication process that leads to death, researchers have learned. By “binding” hypoglycin A, the toxic amino acid found in certain sycamore and box elder tree seeds in the U.K. and other parts of Europe, the charcoal prevents it from entering into the horse’s system, essentially neutralizing it.

“Our study showed for the first time that the toxic amino acid can be bound to activated charcoal,” said Jessika-Maximiliane Cavalleri, DrMedVet, PhD, Dipl. ECEIM, head of Equine Internal Medicine at the University of Veterinary Medicine, Vienna (Vetmeduni Vienna) Equine University Clinic, in Austria.

This finding could help veterinarians react in a goal-oriented manner early in the disease course,” Cavalleri said. “By using activated charcoal to hinder toxin absorption horses might not develop the severe signs if given early enough,” she said.

The activated charcoal—which is highly porous, allowing liquids and gases to seep into it—essentially “traps” certain molecules as they pass through. Once trapped, they cannot get into the bloodstream during the digestive process. In the case of atypical myopathy (AM), the culprit toxins are Hypoglycin A (HGA) and its conjugated metabolites, methylenecyclopropyl acetic acid (MCPA)-carnitine and MCPA-glycine.

Unfortunately, once the toxins have already entered the system and led to severe symptoms, it might be too late for the charcoal therapy.

As such, activated charcoal could be good therapy for “co-grazers,” or horses on the same pastures as clinically ill horses, said Cavalleri. They might have ingested the same seeds and toxins, but they’re not yet showing clinical signs. Activated charcoal administration might help save their lives, she said.

The researchers investigated how activated charcoal would work in the presence of these particular AM toxins when inside the equine intestine (specifically, the jejunum) by applying an established in vitro (laboratory) technique to fresh, healthy samples of horse intestine.

Cavalleri said colleagues Anja Cehak, PhD, Dipl. ECEIM, and Tanja Krägeloh, DrMedVet, found that at a natural pH for the equine small intestine, activated charcoal is highly effective at absorbing HGA. As a result, it limits its release through the intestinal walls into the bloodstream and could reduce or even stop the toxin’s potential effects.

“If further studies confirm our findings, activated charcoal should be given as early as possible in cases where horses have ingested or possibly ingested the seeds responsible for AM,” Cavalleri said.

However, that doesn’t mean owners should start feeding charcoal to their pastured horses “just in case,” she added. Activated charcoal is a therapeutic product developed in a laboratory, a modified form of the charcoal you’d use for building a fire. Furthermore, horses dislike the taste, so the product must be administered through a syringe or nasogastric tube. And finally, charcoal binds not only toxins but also “good” molecules, such as certain nutrients.

“Due to the highly absorptive capacity of the charcoal, a frequent treatment would potentially result in deficiencies of trace elements in the long term,” Cavalleri said. Human studies have also indicated a potential risk of accidental inhalation, which, in horses, can be prevented by using the nasal tube route.

Before giving concrete treatment recommendations, the researchers said they need to see the results of studies performed in live horses.

The study, “Identification of hypoglycin A binding adsorbents as potential preventive measures in co-grazers of atypical myopathy affected horses,” was published in the Equine Veterinary Journal.