title: Increased inflammation and decreased insulin sensitivity indicate metabolic disturbances in zoo-managed compared to free-ranging black rhinoceros (Diceros bicornis).
abstract: Black rhinoceros (rhinos) living in zoos express a host of unusual disease syndromes that are associated with increased morbidity and mortality, including hemolytic anemia, rhabdomyolysis, hepatopathy and ulcerative skin disease, hypophosphatemia and iron overload. We hypothesized that iron overload is a consequence and indicator of disturbances related to inflammation and insulin/glucose metabolism. The objectives of this study were to: (1) generate the first baseline information on biomarkers of inflammation (tumor necrosis factor alpha [TNFα], serum amyloid A [SAA]), insulin sensitivity (insulin, glucose and proxy calculations of insulin sensitivity), phosphate and iron stores (ferritin) using banked serum from free-ranging black rhinos; and (2) then compare serum biomarkers between zoo-managed (n=86 individuals) and free-ranging (n=120) animals. Enzyme immunoassays were validated for serum and then biomarker levels analyzed using mixed models while controlling for sex, age and year of sample collection. Concentrations of TNFα, SAA, insulin and insulin-to glucose ratio were higher (P<0.05) in black rhinos managed in ex situ conditions compared to free-living counterparts. Findings indicate that the captive environment is contributing to increased inflammation and decreased insulin sensitivity in this endangered species.
authors.affiliation: Smithsonian Conservation Biology Institute, 1500 Remount Road, Front Royal, VA 22630, USA; The Wilds, 14000 International Road, Cumberland, OH 43732, USA; Cleveland Metroparks Zoo, 4200 Wildlife Way, Cleveland, OH 44109, USA. Electronic address: mws@clevelandmetroparks.com.
authors.forename: Mandi W
authors.initials: MW
authors.lastname: Schook
authors.affiliation: Smithsonian Conservation Biology Institute, 1500 Remount Road, Front Royal, VA 22630, USA. Electronic address: wildtd@si.edu.
authors.forename: David E
authors.initials: DE
authors.lastname: Wildt
authors.affiliation: Cleveland Metroparks Zoo, 4200 Wildlife Way, Cleveland, OH 44109, USA; Kent State University, 750 Hilltop Dr., 226 Lowry Hall, Kent, OH 44242, USA. Electronic address: mraghant@kent.edu.
authors.forename: Mary Ann
authors.initials: MA
authors.lastname: Raghanti
authors.affiliation: The Wilds, 14000 International Road, Cumberland, OH 43732, USA; Columbus Zoo & Aquarium, 4850 Powell Rd, Powell, OH 43065, USA; The Ohio State University, Department of Veterinary Preventive Medicine, 1920 Coffey Road, Columbus, OH 43210, USA. Electronic address: Barbara.Wolfe@cvm.osu.edu.
authors.forename: Barbara A
authors.initials: BA
authors.lastname: Wolfe
authors.affiliation: Cleveland Metroparks Zoo, 4200 Wildlife Way, Cleveland, OH 44109, USA; The Ohio State University, Department of Veterinary Preventive Medicine, 1920 Coffey Road, Columbus, OH 43210, USA. Electronic address: pmd@clevelandmetroparks.com.
authors.forename: Patricia M
authors.initials: PM
authors.lastname: Dennis
mesh_terms: D000818:Animals; D000835:Animals, Wild / Q000378:metabolism*; D000836:Animals, Zoo / Q000378:metabolism*; D015415:Biomarkers / Q000378:metabolism; D005260:Female; D007249:Inflammation / Q000188:drug therapy / Q000209:etiology / Q000378:metabolism* / Q000662:veterinary*; D007328:Insulin / Q000494:pharmacology*; D007333:Insulin Resistance; D008297:Male; D010527:Perissodactyla / Q000378:metabolism*
chemical_list: D015415:Biomarkers; D007328:Insulin
keywords: Black rhinoceros; Glucose; Hemochromatosis; Inflammation; Insulin; Iron overload