Reticuloendotheliosis in captive greater (Tympanuchus cupido pinnatus) and Attwater's (T. cupido attwateri) prairie chickens is reported for the first time. Between September 1993 and August 1994, two adult female wild-caught greater prairie chickens housed at Texas A&M University (College Station, Texas, USA) were observed with multiple subcutaneous nodules. Both birds were euthanatized. Complete necropsy examinations revealed lesions limited to the skin of each bird. Histopathologic examination of lesions revealed pleomorphic lymphoreticular cells suggestive of
reticuloendotheliosis and reticuloendotheliosis virus (REV) was demonstrated in
tumor tissue by polymerase chain reaction and virus isolation. Between September 1994 and June 1995, five additional greater prairie chickens and two Attwater's prairie chickens were euthanatized or found dead with evidence of lymphoreticular
neoplasia in multiple organ systems. Initial testing of the captive flock in December 1994 for evidence of
viremia and antibody to reticuloendotheliosis virus revealed over 50% of the tested birds were viremic, but none developed
antibodies. Subsequent testing between January 1995 and January 1996 indicated that once infected with reticuloendotheliosis virus, Attwater's prairie chickens tended to remain outwardly healthy despite persistent
viremia compared to infected greater prairie chickens which had higher morbidity and mortality rates within 60 to 90 days after initial detection of
viremia and did not usually develop persistent
viremia.
Antibodies to REV were detected in only three captive greater prairie chickens and only in 1995. Six of the nine birds that were euthanatized or found dead due to
reticuloendotheliosis developed
viremia prior to death; three birds were not tested prior to death. Testing of free-ranging greater and Attwater's prairie chickens for
reticuloendotheliosis is recommended prior to translocation or release.