Copper Drench Inhalation in Young Lambs

_{Inhalation of copper-containing drench can be fatal in lambs.}

It is not uncommon for us to see cases of lamb mortality due to copper-containing drench inhalation at this time of year. Affected flocks often report several losses following administration of a mineral drench containing copper. Usually this is seen in lambs that have had undergone multiple procedures at handling (e.g. vaccination, plus worm drench, plus mineral drench). Some affected lambs exhibit coughing and respiratory distress following drench administration, whereas others show no clinical signs prior to death. Affected animals tend to die within 15 minutes – 24 hours following treatment. A chemical pneumonopathy is the cause of death in these animals.

Postmortem examination on such lambs may show some evidence of lung congestion and consolidation, but histopathology is required to confirm the diagnosis: airway necrosis will be evident, consistent with the recent inhalation of an irritant substance. In addition, copper analysis of lung tissue shows higher than normal results.

These cases highlight the need for care when administering oral drenches to young lambs, and demonstrate the importance of farmer education. While it may not be practical to split procedures over two handling sessions, it is important to stress to farmer the importance of sympathetic handling and to be mindful of the potential stresses on lambs during these procedures.

Findings from a brief postmortem could be mistaken for Pasteurellosis or pulpy kidney disease. A history of recent handling and treatments should prompt further investigation and allow the correct diagnosis to be reached.

Posted by SRUC Veterinary Services on 25/06/2021