A Disease of Manx Shearwaters (Puffinus puffinus)

1. An epizootic among Manx shearwaters (Puffinus p. puffinus) was observed on Skomer island in September 1947. It had many features in common with an epizootic observed there in the autumn of 1946; the chief point of difference between the epizootics being the absence of any cases of conjunctivitis in 1947. 2. The signs of the disease were found in juvenile shearwaters, generally between 70 and 75 days old. 3. The principal lesions of the disease were blisters on the webs of the feet and small areas of consolidation in the lungs. 4. Fatality was probably high; the morbidity rate varied with the locality. 5. Evidence was obtained that the incubation period of the disease was about 8 days or less, and that the most likely mode of transmission was by contact of the webbed foot with soil or stones contaminated from burst blisters. 6. The manner in which an epizootic arises is obscure, and it is possible that other hosts exist besides the shearwater.