HISTOPATHOLOGICAL CHANGES IN THE LYMPHOID-TISSUES OF SHEEP EXPOSED TOTHE BOVINE IMMUNODEFICIENCY-LIKE VIRUS

Six yearling sheep were inoculated intraperitoneally with peripheral b lood from two sheep infected with the bovine immunodeficiency-like vir us (BIV) strain R29. An additional five sheep served as sham-inoculate d controls. Of the six sheep given BIV, five seroconverted, one of the m remaining seropositive for the duration of the study. The polymerase chain reaction demonstrated BTV provirus in three of the five serolog ically positive animals. At necropsy, 1 year after inoculation, histol ogical changes were found only in the lymphoid tissues. In sheep expos ed to BTV, mild though significant increases were seen in the (1) numb er of splenic periarteriolar lymphoid sheaths, (2) number of secondary follicles in hilar and prescapular or popliteal lymph nodes, and (3) medullary sinus cellularity in prescapular and popliteal lymph nodes. (C) 1996 W.B. Saunders Company Limited