Cladosporium Infection in a Captive Bottlenose Dolphin (Tursiops truncatus): A Rare Case Report from Quanzhou, China.

This case report describes a male bottlenose dolphin (Tursiops truncatus) from a republic aquarium in Quanzhou City, Fujian Province, China, in 2024. The dolphin exhibited prolonged vomiting that did not improve despite extended antibiotic treatment, followed by progressive deterioration in physical condition until death. Antemortem biochemical analyses indicated hepatic dysfunction (ALT: 269.8 IU/L, AST: 1357.5 IU/L, LDH: 2913.3 IU/L) and renal impairment (TBIL: 55.84 μmol/L, BUN: 31.93 mmol/L, Cr: 200.2 μmol/L). Necropsy showed atrophy of coronary fat in the heart, hepatomegaly with extensive yellow discoloration, splenomegaly with congestion, diffuse dark-red discoloration of the lungs, renal atrophy, segmental dark-red discoloration of the intestines, and dark-red enlargement of intestinal lymph nodes. Histopathological examination revealed hepatic steatosis with necrosis, extensive pulmonary hemorrhage with foreign bodies in the trachea and alveoli, intestinal necrosis with visible fungus, and congestion and necrosis of intestinal lymph nodes with visible fungus present; the fungus hyphae were periodic acid-Schiff (PAS)-positive. Fungal PCR targeting the fungus internal transcribed spacer (ITS) region identified the intestine fungus as Cladosporium. Infection with Cladosporium is extremely rare, and this report highlights the potential risks of emerging infectious diseases in marine mammals.