Sterile nodular panniculitis with lung and lymph node involvement in a Siberian tiger (Panthera tigris altica)

HU, Shou-Ping; ZHANG, Zhuo; ZHANG, Jiao-Er; CAI, Xue-Hui; NAKAYAMA, Hiroyuki; HE, Xi-Jun

A 2-to 4-year-old uncastrated male Siberian tiger bred in a local wild animal park presented with generalized clinical signs including abdominal pain, fever, lethargy, and anorexia. The tiger presented with dermal nodules along the trunk and peculiar masses within the abdominal cavity on palpation. The patient subsequently died of chronic, progressive dyspnea despite 45 days of antibiotic treatment. A necropsy was performed within 5 hr of death. Several subcutaneous nodules were present along the abdomen, chest, and back. The dermal nodules were solid, exhibited limited mobility, and varied in size. The largest mass measured 8.5 cm in diameter, while the smallest measured 2.0 cm in diameter. None of the masses showed ulceration or hemorrhage. Similar nodules were also observed within the intraperitoneal fat tissues, including the omental, mesenteric, and perirenal fat. The intraperitoneal nodules were irregular and varied in size from 0.5-10 cm in diameter. The nodules varied in color doi: 10.1292/jvms.17-0262 from red-brown to pale yellow foci resembling fat necrosis, and the cut surface of the nodules was red-gray to pale yellow ( Fig. 1 ). The mesentery was markedly thickened, and the normal lobulation of the fat tissue was absent. Small irregular white-gray spots were studded on the mesentery (Fig. 2) .