Edema disease in two gold-spotted pond frogs (Pelophylax chosenicus) raised in captivity: two case reports

Two gold-spotted pond frogs (Pelophylax chosenicus) experienced anorexia, buoyancy without diving, and systemic swelling for 1 month and died several days later. On necropsy, the liver had protruding dark gray nodules scattered on its surface, and the kidneys were fat-like beige. Bacteriology showed the presence of Citrobacter braakii, Delftia acidovorans, Elizabethkingia spp., and Chryseobacterium indologenes. On microscopy, the liver showed melanomacrophagic aggregates, inflammatory cell infiltration, and fibrosis. In the case of these frogs, the edema disease is suspected to have been caused by long-term exposure to chlorine and chloramines in tap water rather than infection.