Coffee senna (Senna occidentalis), previously referred to as Cassia occidentalis, is an upright annual or biennial shrub of the Fabaceae family. S. occidentalis has branched stems which are initially reddish-purple but turn greenish-brown as they mature. It produces clusters of bright yellow flowers and dark brown, flattened, sickle-shaped pods.
Poisoning Cases of Coffee Senna
All parts of S. occidentalis are toxic to horses if ingested. 20 mares were poisoned from being fed ground corn that had been contaminated with 8% S. occidentalis. 60% of the affected horses (12/20) died as a result of the poisoning; 8 were found dead, the other 4 developed hepatic encephalopathy and either died or were put down after developing clinical signs. The other 40% of affected horses developed mild depression and decreased appetite.