The highly mobile nature of modern-day domestic horses has been highlighted in a study in Ontario, Canada.
The findings of the University of Guelph research point to the somewhat unique nature of horse movements when compared with livestock such as cattle and sheep.
The movement of livestock is one of the key drivers of infectious disease introduction and spread.
Kelsey Spence and her colleagues, writing in the open-access journal PLOS ONE, noted that while many countries have traceability requirements for livestock, similar programs are often difficult to implement in horse populations.
“Horses are a highly mobile population, with many travelling locally, nationally, and internationally to participate in shows and sporting events,” the study team said.
“However, the nature and extent of these movements, as well as the potential impact they may have on disease introduction and spread, is not well documented.”
For their study, Spence, Terri O’Sullivan, Zvonimir Poljak and Amy Greer explored the movement network of a sample of horses in Ontario over a seven-month equestrian season.
A total of 141 horse owners documented their travel patterns involving 330 horses by completing monthly online questionnaires.
A total of 1754 horse movements were reported, involving a variety of location types. Many of the destinations were parks, trails, and private farms.
There were 553 unique locations attended by horses over the seven months. Of those, 97% were in Ontario.
Seven trips involved crossing into the United States.
Only 34.3 percent of competitions attended by participants during the study period were regulated by an official equestrian organisation.
“Organisers of unsanctioned events are not required to implement disease prevention strategies, and potentially have higher risks of disease introduction and spread associated with attendance,” the study team noted.
“Thus, the unique nature of horses as companion animals should be considered when determining the most effective way to introduce traceability requirements.”
Participants tended not to travel to the same locations each month, and the most connected locations varied between consecutive months.
“While the findings should not be generalized to the wider horse population, they have provided greater insight into the nature and extent of observed horse movement patterns.”
Horses tended to travel on weekends and usually travelled short distances (less than 50km) between locations.
“A higher frequency of local, within-region travel suggests that potential disease spread originating at a given location would have a higher probability of being contained in that region, as the majority of contacts would be in close geographic proximity,” the researchers said.
“Mechanisms to ensure that potential disease spread or exposure is detected quickly at horse facilities should be in place to reduce the risk of local or international disease spread.
Discussing their findings, the researchers said the use of horses for companionship introduced opportunities to travel to unconventional locations, which may have important implications for disease risk.
“Thus, the unique nature of horses kept as companion animals should be considered when determining effective methods for disease prevention and control.”
The findings, they said, supported the need to better understand the variety of locations to which horses can travel in Ontario, as different types of locations may have different associated risks of disease introduction and spread.
“The outcomes from this study could be used to support future research to examine and refine disease prevention, control, and surveillance strategies in the population.”
Spence KL, O’Sullivan TL, Poljak Z, Greer AL (2019) Descriptive analysis of horse movement networks during the 2015 equestrian season in Ontario, Canada. PLoS ONE 14(7): e0219771. https://doi.org/10.1371/journal.pone.0219771