A recent retrospective study of causes of morbidity and mortality in red wolves (Canis rufus) revealed a high prevalence of lesions consistent with inflammatory bowel disease (IBD).2 Subsequent research demonstrated that red wolves lack certain protective alleles that may predispose them to developing IBD.1 The present study describes the demographic and clinicopathologic characteristics of a subset of red wolves (n=20) with IBD-like lesions diagnosed histologically from endoscopically collected samples or from postmortem specimens. The wolves (9.11) ranged in age from 1–13.58 yr (median age 6.53 yr). Inflammatory lesions were characterized by anatomic location (stomach, duodenum, colon), degree of inflammation (mild, mild-moderate, moderate, moderate-severe, severe), and predominant cell type (lymphocytic, plasmacytic, eosinophilic, neutrophilic, or histiocytic). The duodenum was the site of most consistent and severe inflammation (n=17) with lymphoplasmacytic/eosinophilic inflammation being most common (n=10). Gastric inflammation (n=9) was always accompanied by intestinal inflammation and was predominantly lymphoplasmacytic (n=3) or lymphoplasmacytic/eosinophilic (n=3). Colonic inflammation was restricted to a single wolf and was characterized as moderate lymphoplasmacytic/eosinophilic. Regardless of anatomic location, the majority of lesions were considered subclinical. Five wolves were diagnosed with moderate-severe or severe gastritis and/or enteritis. The wolves with severe enteric lesions demonstrated hypocholesterolemia, hypoproteinemia, hypoalbuminemia, hypocalcemia, and low serum folate, as commonly seen in domestic dogs with IBD. Inflammatory bowel disease is a common finding in red wolves and follows a similar clinical course as seen in the domestic dog. This research provides the first steps to understanding this syndrome in the critically endangered red wolf.
The authors thank the animal care and veterinary staff at the North Carolina Zoo, North Carolina State University College of Veterinary Medicine, Akron Zoo, and the Point Defiance Zoo & Aquarium for their participation in this study and for the care of these animals.
1. Henson LH, Songsasen N, Waddell W, Wolf KN, Emmons L, Gonzalez S, Freeman E, Maldonado J. Characterization of genetic variation and basis of inflammatory bowel disease in the Toll-like receptor 5 gene of the red wolf and the maned wolf. Endang Species Res. 2017;32:135–144.
2. Seeley KE, Garner MM, Waddell WT, Wolf KN. A survey of diseases in captive red wolves (Canis rufus), 1997–2012. J Zoo Wildl Med. 2016;47(1):83–90.