An epizootic of fowl cholera (Pasteurella multocida), in lesser snow geese (Chen h. hyperborea), blue geese (Chen caerulescens), mallards (Anas platyrhynchos), and other waterfowl occurred on Squaw Creek National Wildlife Refuge, Holt County, Missouri, during early January, 1964. More than 1,000 geese died in one night. Symptoms and previous case histories of fowl cholera, an infrequently reported disease among wild waterfowl, are reviewed. Pertinent field observations and methods of diagnosis are described. Observations indicated that mallard ducks were the probable early carriers of the disease. Snow, blue, and small Canada geese (Branta c. hutchinsii) were quite susceptible while large Canada geese (Branta c. interior and maxima) were not involved. Stresses caused by limited open water, overcrowding of birds, and inclement weather may have been conducive to the epizootic. Direct mortality from fowl cholera on wintering areas is not indicative of total mortality. Losses may continue along the migration routes. Secondary effects may result in loss of productivity. This paper describes an epizootic of fowl cholera (Pasteurella multocida) in lesser snow and blue geese and other waterfowl on Squaw Creek National Wildlife Refuge, Holt County, Missouri, during late 1963 and early 1964. Fowl cholera is a serious disease of domestic fowl, but it is infrequently reported as an epizootic disease of wild waterfowl. The earliest documented record of fowl cholera in wild ducks was reported by Quortrup et al. (1946) in Texas. Petrides and Bryant (1951) reported that periodic outbreaks of fowl cholera among ducks have occurred there since. The largest reported losses occurred in California where Sperry (1949 unpublished report filed at Patuxent Wildlife Research Center, Laurel, Maryland) estimated a die-off of 36,000 ducks. Rosen and Bischoff (1950) reported losses of coots, ducks, and gulls to Pasteurella multocida over a broad coastal area near San Francisco Bay. More recently, in Maine, a fowl cholera outbreak in eider ducks (Somateria mollissima) was reported by Gershman et al. (1964). The absence of signs of disease before death from fowl cholera has been recorded in numerous cases. Curtice (1902) reported a case in domestic geese where some specimens in prime condition were found dead with scarcely any appearance of previous sickness. Quortrup et al. (1946:99) observed that 10 minutes before death, ducks were apparently in good health except that normal reflexes were not as sensitive as in healthy birds, and they did not become frightened so easily. They also noted, Many birds died with their heads up in a natural sitting position and rigor mortis was immediate. Rosen and Bischoff (1949: 186) observed ducks in normal flight or in loafing attitudes, or else the carcasses were seen floating on the ponds or lying along the shoreline. Barger et al. (1958) reported that, when the disease was very acute, the first indication of infection was the finding of dead chickens that had not shown any signs before death. They also found that ex1 This project was supported by Federal Aid to Wildlife Restoration, Surveys and Investigation Projects, Missouri 13-R; by funds from the Department of Veterinary Microbiology, University of Missouri; and by funds from the Bureau of Sport Fisheries and Wildlife, Squaw Creek National Wildlife Refuge.