BY THELATE sixteenth century, the Ottomans reigned over vast stretches of territory in three continents, covering all or part of thirty present-day countries. Their empire's subjects numbered as many as thirty-five million, and its animals many more. Their capital city and their military, by far the largest in Europe, were supplied from distant provinces with countless ships and caravans of provisions, and herds of sheep and cattle. These were tremendous achievements for an early modern empire—and also tremendous opportunities for some enterprising microbes, especially among the Ottomans’ large, vulnerable, and mobile population of livestock.

This chapter examines the history of a devastating but little-known pestilence of Ottoman sheep and cattle in the 1590s, and it makes the case that this contagion set a pattern for major European epizootics (animal epidemics) over the following century and a half. The first part explains how the Ottoman livestock pestilence arose from a conjuncture of three circumstances: rising stock densities and diminishing pasturage; expanding animal supply lines and pressures on supplies during military campaigns; and the recurrence of severe winters typical of the Little Ice Age. These factors aligned to produce a widespread contagion that wiped out as many as nine in ten sheep and cattle over much of the empire, contributing to severe famine, flight, and violence. The second part of the chapter examines how Europe witnessed a similar combination of ecological pressures during the eigh-teenth century, with similar consequences for its livestock. Changing cattle supply lines and the untimely combination of severe winters and military campaigns triggered Europe-wide panzootics (animal pandemics) of rinderpest in the 1710s and 1740s resulting in losses of millions of cattle. The third and final part of this essay reconsiders some conventional narratives in the history of veterinary medicine in light of these findings. The few scholars who have written on the history of early modern epizootics have tended to champion the early proponents of contagion theories and their efforts to contain invading diseases of livestock, especially in response to the 1710s and 1740s rinderpest outbreaks. Yet contemporary observers, including contagionists, also emphasized local environmental factors in epizootic outbreaks, and their observations should be appreciated as more than mere holdovers from pre-contagionist Galenic medical thought.