Do Alberta’s feral horses self-medicate with plants to fight off parasites? 

A University of Calgary Faculty of Veterinary Medicine (UCVM) research project is looking to see if feral horses are ‘self-medicating’ with plants that have anti-parasitic properties. The study, funded by the Margaret Gunn Endowment for Animal Research, aims to discover new information of benefit to veterinary and potentially human medicine.

“Historically, traditional knowledge of medicinal plants used to treat human ailments has led to the discovery of many medically important compounds,” says Dr. Brielle Rosa, DVM, PhD, an assistant professor of veterinary pharmacology at UCVM. “But there’s been little investigation of Indigenous knowledge of plant-derived medications for veterinary use.”

Zoopharmacognosy, or self-medication, by animals has never been studied in horses. “But there are anecdotal reports of horses eating plants that have little nutritional value but that may have medicinal value,” says Rosa.

Plants chosen for study guided by local Indigenous knowledge keepers

Rosa is collaborating with Brenda Holder, a traditional knowledge keeper of plant medicine and member of the Métis Nation of Alberta.

“This is a really important collaboration for me to help bring forward some of these skills, knowledge, traditions, and culture from Indigenous Peoples,” says Holder.

Traditional Indigenous knowledge is integrated in the research project to identity which plants may have medicinal value. Rosa says the parasites in feral horses are similar to the parasites of domestic horses. And while they haven’t done the DNA analysis of samples yet, based on fecal egg counts it appears that strongyles — nematode worms in the gastrointestinal tract — are the predominant type of parasites present.  

“This project is a novel approach to anti-parasitic drug discovery,” says Rosa.

Summer students help observe plant-eating habits of feral horses near Sundre

Through the Indigenous Summer Student Program, two UCalgary students were hired to participate in this research project. Kobe Belhumeur, who belongs to the Sapotaweyak Cree Nation, is a third-year chemistry student.

“I applied for this program because I saw it as an amazing opportunity to get experience in the field I want to go into in my future and I also really love being outdoors and the Indigenous aspect of learning more about my culture.”

Morgan Hughes is a fourth-year ecology student and member of the Métis Nation of Alberta. The program and research study combine her passion for ecology and veterinary medicine, as well as giving her the opportunity to learn more about traditional knowledge of plants.

“I was excited to be a part of this project because it will really help further my education. I’m hopefully going into vet med in the future.”

The year-and-a half-long research project consists of field work and data collection. Over the summer, Rosa, Holder, and the two students observed several bands of feral horses in the Sundre area, using a combination of remote cameras and direct observations to see what plants they were eating that may have anti-parasitic properties. They also took samples to determine the parasite loads of the horses; this will allow them to determine if there is a correlation between parasite burden and the plants ingested.

“This research may lead to the identification of novel antiparasitic agents, which would benefit both animal and human health,” says Rosa. Plants identified through this work as having likely antiparasitic activity will be further investigated in Rosa’s laboratory. Belhumeur and Hughes are also continuing their work on the project throughout the school year.