Abstract
Necropsy results for 192 adult (8 months or older) Attwater’s prairie chickens (Tympanuchus cupido attwateri) were examined to determine the incidence of neoplasia from 2004 to 2010. Lymphosarcoma and squamous cell carcinoma were the predominant types of neoplasia identified on histopathology. Both tumor types are among the most commonly seen in galliformes.1 Lymphosarcoma was found on necropsy in 9 cases (4.7%). Four additional cases (2.08%) were suspicious for lymphosarcoma but unconfirmed on histopathology. Lymphosarcoma findings were associated with an outbreak of reticuloendotheliosis virus (REV) infections, and all birds tested positive for REV. REV is a retrovirus infecting ducks, geese, turkeys, quail, pheasants, and chickens that is associated with immunosuppression and subsequent secondary infections, as well as tumor formation in the kidneys, bursa, gonads, or digestive tract. Tumors that can occur include lymphomas, lymphosarcomas, adenomas, and carcinomas.2 The affected Attwater’s prairie-chickens (APCs) ranged in age from 10 months to 8 years with an average age of 3.8 years at death. One bird (0.52%) was identified with a histiocytic sarcoma that was thought likely to be associated with REV infection. Squamous cell carcinoma (SCC) was found in the oral cavity of six birds (3.1%). SCC is one of the most common oral tumors in birds3 but is less commonly reported than other forms.4-7 SCC was found only in APCs over 5 years of age with an average age of 7 years. In this captive collection, young birds were more likely to die with neoplasia associated with an infectious disease, while SCC was found in aged birds only.
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