Monensis toxicity in lambs.

A group of 100 purebred lambs was accidentally fed ten times the prescribed level of monensin in its grower ration. The first clinical sign was feed refusal. When the lambs were forced to eat the ration by withdrawal of other feeds, clinical signs developed within 48 hours in 15 to 20% of the group. These included recumbency, inability to rise, stiff gaits and a tendency to walk on their toes. Clinical examination, history, laboratory and necropsy results, along with feed analysis confirmed the diagnosis of monensin toxicosis.