The water sample was forwarded to the Public Health Laboratory in Bismarck, North Dakota for examination. Analysis of the water sample showed a pure culture of Anabaena flos-aquae . In the absence of significant microscopic changes and considering the clinical history and proximity of the contaminated stock pond, a diagnosis of cyanobacteria toxicosis was made. Anabaena flos-aquae is a cyanobacteria which produces a toxin known as very fast death factor. This toxin is a tertiary amine which causes respiratory paralysis in as little as five minutes after ingestion.
Typical cases occur in the late summer when hot conditions favor cyanobacterial growth.
The organisms became windblown and aggregate on the leeward side of stagnant ponds where animals ingest them while drinking water. Treatment is usually unsuccessful and the problem is instead approached through management, either by fencing the pond from animal access or treating the water with copper sulfate. Bison with respiratory distress A chronically ill adult female bison was submitted to the NDSU-VDL for necropsy. Fibrous pulmonary adhesions were present between the parietal and visceral pleura adjacent to the areas of fracture. There was focally extensive nodular thickening of the abomasal mucosa.