Nitrate Poisoning due to Ingestion of Cabbages (Brassica oleracea var. capitata L.) (Brassicaceae) in Kitui County, Kenya

Abstract

Nitrate toxicosis associated with consumption of cabbages (Brassica oleracea var. capitata L.) (Brassicaceae) was diagnosed in a small herd comprising of ten goats in Matinyani ward, Kitui West sub-County of Kitui County in Kenya. The clinical signs were ataxia, ruminal tympany, bluish-brown mucous membranes, rapid and difficult breathing, incoordination, head pressing, aggressive movements, jugular distension, increased heart rates, tremors, and coma. Six goats died of intoxication. Dark brown/chocolate-colored and poorly clotted blood was the prominent necropsy finding. There was limited froth in the trachea and bronchi consistent with mild pulmonary oedema. There were liver congestion, pericarditis, and enlarged and congested kidneys with pinpoint haemorrhages. Four other affected goats were treated with intramuscular antihistamines and oral administration of ivermectin. No further mortality was observed after the treatment. Cabbages fed to goats had 6.6% nitrate on dry matter (DM) basis, while ruminal contents had 5.55% nitrate on dry matter basis (DM). Dark brown blood collected at postmortem had a methemoglobin fraction of 78%. Forage nitrate levels of 0.5% and above are potentially dangerous, with acute poisoning likely to occur if the nitrate level exceeds 1%. Death can occur when blood methemoglobin levels rise up to 67-90%. Findings from the current study are indicative of nitrate-nitrite toxidrome associated with ingestion of cabbages.