On the horse sickness

Abstract

This article presents one of the earliest detailed clinical, pathological, and epidemiological accounts of the disease historically known as “Horse Sickness” in the Cape Colony, now recognised as African horse sickness. Drawing on nine years of observation in the Graaff-Reinet district, District Surgeon Thomas Perry reports on the disease’s symptoms, progression, environmental triggers, and fatal outcomes. He documents repeated outbreaks from 1819 to 1829, noting extremely high mortality rates among horses and the rapid course of the illness. Perry offers meticulous post-mortem observations—including severe pulmonary inflammation, congestion, and the presence of yellow frothy exudate in the lungs and trachea—identifying respiratory obstruction as the immediate cause of death.

The paper also evaluates local beliefs, treatment attempts, and preventative practices. Perry argues that early intervention through aggressive bleeding, purgatives, and counter-irritation may offer limited benefit but only if administered at the very onset of symptoms, which are often subtle. He rejects the notion that the disease is infectious, suggesting instead an atmospheric or climatic cause linked to sudden temperature changes and exposure to cold, particularly in low-lying “Thornveld” areas. High-altitude grazing lands are proposed as the safest preventative measure. The article represents a foundational historical record of African horse sickness pathology, veterinary practice, and environmental understanding in early 19th-century Southern Africa.