Map of the Great Epizootic of 1872-73. Each point on the map documents when the disease was first reported to have arrived in that city, based on firsthand observations of infected horses.
In 1872-73, horses in Toronto infected nearly all urban horses in Canada and the US with an unknown disease (likely equine influenza). This map shows that extraordinary story.
Above is an animated map of the Great Epizootic of 1872-73, showing its arrival in 164 Canadian and US cities and towns between September 29, 1872 and September 28, 1873. If you click the “play” button at the bottom of the map, you can watch the spread of this disease that infected urban horses across Canada and the US during this period, incapacitating the animals and preventing them from working. You can also click on each infected city to see the sources used to determine what date the disease arrived.
I built this map using more than 480 newspaper articles, veterinary reports, and other contemporary accounts of the epizootic. These historical documents allowed me to approximate the arrival of the disease in each city to within a couple of days and then plot that information in a Geographic Information System database in ArcGIS. Using the Time Aware tool from ArcGIS Online, I was then able to animate this historical geographic information and observe how the epizootic spread throughout the continent. This work was inspired by the excellent book, Historical GIS Research in Canada.
The results proved quite interesting and I would encourage readers to take a look at a new article that I published based on this HGIS project. You can find it in Environmental History (July 2018) right here. It outlines the main findings from the map, highlighting relationships among humans, horses, railroads, and urban environments. In this article, I argue that the Great Epizootic provides evidence that networked urbanization produced forms of historical biotic homogenization that could result in the rapid and widespread outbreak of animal disease. I blend urban environmental history, animal history, histories of health and disease, and history of science to better understand this remarkable event.
The research for this article is part of my ongoing project on the history of urban animals in Canada. Readers can find out more about this project on my research page here:
Latest posts by Sean Kheraj (see all)
- Nature’s Past Episode 66: Communicating Toxic Legacies - October 16, 2019
- Nature’s Past Episode 65: 3rd World Congress of Environmental History - August 15, 2019
- How to Build the World’s Largest Oil Pipeline System - July 18, 2019
- Nature’s Past Episode 64: Environment and Alibi - May 22, 2019
- From Field Trip to Walking Tour: Animals in the City - April 30, 2019
- What Role Should History Play in Canadian Oil Pipeline Politics? - April 16, 2019
- Building Environmental History Networks Around the World - April 12, 2019
- I’m Not Going to Ohio: How I Will Participate in ASEH 2019 - April 11, 2019
- More: Energy History and Energy Futures - April 10, 2019
- Nature’s Past Episode 63: Unbuilt Environments - March 25, 2019