Possible monensin poisoning in a group of bulls.

Apparent monensin toxicity was diagnosed in a group of Maine Anjou bulls placed on a performance test in a commercial feedyard in east central Saskatchewan. The clinical, hematological and pathological findings were consistent with a diagnosis of congestive heart failure. The suspected dose ingested by the bulls was based on a mixing error evident from the feedlot's daily feed journal. When deaths in the group of bulls began to occur, the intoxicating feedstuff was no longer available for confirmation of the diagnosis.