Microscopic lesions caused by helminths discussed in this paper are verminous pneumonia, gastric ulcers, and ulcerative enterocolitis in the California sea lion (Zalophus californianus); biliary fibrosis and pulmonary granulomas in the dall porpoise (Phocoenoides dalli); and gastric fibrosis in an Atlantic bottlenose dolphin (Tursiops truncatus) and a Pacific bottlenose dolphin (Tursiops gilli).
