Tiamulin and narasin toxicosis in nursery pigs

This case report describes a clinical case of tiamulin and narasin toxicosis in a group of nursery pigs, caused by the inadvertent introduction of narasin at 83.1 g per tonne into a ration containing tiamulin at 31.4 g per tonne. The affected pigs were anorexic and showed signs of weakness, depression, ataxia, and incoordination to the point of recumbency, without paddling or other neurological signs. Pathologically, a diffuse, extensive degenerative myopathy was present. The feed-mixing error was caused by a mechanical problem with the microingredient discharge equipment at the feed mill. Steps were taken by the feed manufacturer to correct and prevent the occurrence of another incident.