Dicumarol toxicity in a herd of Ayrshire cattle fed moldy sweet clover

Abstract

An outbreak of sweet clover poisoning is reported in a herd of 12 yearling Ayrshire heifers. Symptoms included lameness, epistaxis, subcutaneous haematomas, shivering and depression. Four animals died, 2 possible early embryonic deaths occurred and one cow aborted. The remaining animals responded to vitamin K1 treatment and there were no recurrences or further complications. Toxicological screening of the haylage fed to the heifers revealed levels of 20.0-27.7 p.p.m. dicoumarol. Liver samples submitted from a necropsied animal yielded levels of 1.1 p.p.m. dicoumarol, confirming the diagnosis of sweet clover poisoning.