INTERSTITIAL MASTITIS IN MAEDI-VISNA VIRUS-INFECTED EWES

Serological examination of blood samples and histopathological examina tion of lungs, udder and supramammary lymph nodes were carried out in case of 86 culled, 4 to 8 years old ewes originating from three maedi- visna virus infected sheep flocks. Antibodies were demonstrated by AGI D-test in 59 animals (68.7%). Histopathological changes characteristic for maedi-disease were found in the lungs and udder of 36 seropositiv e and 7 seronegative ewes (Tables 1 and 2). In the udders, affecting b oth udder-halves, subacute, proliferative-type interstitial inflammati on was found together with the atrophy of glandular substance, fibrosi s and formation of lymphoid follicles (Figs 2, 3 and 4). Follicular an d paracortical lymphoid hyperplasia was found in the supramammary lymp h nodes. Based on the pathognostic alterations found in the udders, th e occurrence of interstitial, lymphocytic inflammation associated with maedi-visna infection seems to be confirmed in the Hungarian sheep fl ocks. Based on the histopathological changes found in 50% of the culle d ewes, the authors have the opinion that maedi-disease is one of the most frequent causes of diminished life production and thus it causes significant economical losses.