Blue-green algae (Anabaena spiroides) toxicosis in pigs

Toxicosis caused by Anabaena spiroides was diagnosed in 7 of 26 finishing hogs in a farrow-to-finish operation in Kentucky. Several sick pigs in the herd had the following clinical signs: vomiting, dull appearance, lethargy, anorexia, muscle tremors, frothing at the mouth, coughing, sneezing, dyspnea, and bloody diarrhea. Of the 7 dead pigs, 2 were necropsied. Tissue speciments and stomach contents were obtained for microscopic, microbiologic, and toxicologic evaluations. In addition, vomitus from sick pigs and pond water samples were collected for laboratory analysis. Direct microscopic examination of pond water, vomitus, and stomach contents revealed nearly pure A spiroides, a toxic blue-green algae. The possible involvement of bacterial toxins in these pigs was not established; however, the laboratory and field data suggested that the clinical signs and death losses were attributable to the consumption of pond water mixed with the bloom of the alga, A spiroides.