Abstract: | The occurrence of the papillomatous disease of the coypu having a contagious character was recorded for the first time in Czechoslovakia in 1975. The papillomatous lesions of the size of a pea to bean occurred on the skin of the extremities, tail head and in the oral and nasal cavities. The females were affected first, followed by their young and then by the young borne by healthy mothers after contact with the diseased animals. On the whole the disease affected 57 animals (60%). The disease spontaneously disappeared within 2.5 to 3.5 months of the occurrence of the papillomatous lesions. The virus etiology of the disease was demonstrated by means of the electron-microscopic detection of virus particles the structure of which corresponded to that of the papillomatous viruses. |