viruses Article A Novel Retrovirus (Gunnison’s Prairie Dog Retrovirus) Associated With Thymic Lymphoma in Gunnison’s Prairie Dogs in Colorado, USA Molly D. Butler 1, Karen Griffin 2, Connie D. Brewster 1 , Marylee L. Kapuscinski 1, Mark D. Stenglein 1 , Daniel W. Tripp 2, Sandra L. Quackenbush 1,* and Karen A. Fox 2,* 1 Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO 80523, USA;
[email protected] (M.D.B.);
[email protected] (C.D.B.);
[email protected] (M.L.K.);
[email protected] (M.D.S.) 2 Colorado Division of Parks and Wildlife, Wildlife Health Laboratory, Fort Collins, CO 80521, USA; karen.griffi
[email protected] (K.G.);
[email protected] (D.W.T.) * Correspondence:
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[email protected] (K.A.F.); Tel.: 1-970-491-3545 (S.L.Q.); Tel: 1-970-472-4318 (K.A.F.) Received: 8 May 2020; Accepted: 31 May 2020; Published: 2 June 2020 Abstract: As part of research and wildlife disease surveillance efforts, we performed necropsy examinations of 125 free-ranging (n = 114) and captive (n = 11) prairie dogs in Colorado from 2009 to 2017. From these cases, we identified three cases of thymic lymphoma in free-ranging Gunnison’s prairie dogs (Cynomys gunnisoni), and we identified a novel retroviral sequence associated with these tumors. The viral sequence is 7700 nucleotides in length and exhibits a genetic organization that is consistent with the characteristics of a type D betaretrovirus.