Acute interstitial pneumonitis caused by Aleutian disease virus in mink kits.

In four Danish mink ranches acute interstitial pneumonitis caused excessive mortality among kits within the first 2 1/2 months after parturition. The disease was found to be due to an Aleutian disease virus (ADV) and could be reproduced experimentally in neonatal kits by inoculation with material from spontaneous cases, as well as with other strains of ADV. Experimental reproduction was only possible in kits from dams free of Aleutian disease (AD) whereas kits from dams experimentally or naturally infected with ADV developed no lung changes. Presently available evidence indicates that the initial lung lesions result from primary viral injury to type II alveolar cells, and that immune mechanisms, essential for the development of traditional AD, are not involved in the pathogenesis.