Three dead lambs sent to the Department of Agriculture’s regional veterinary lab in Athlone were found to have died from poisoning.

The eight-month-old lambs were sent to the lab after dying suddenly not long after breaking out from the field they were grazing.

Vets at the lab conducted a post mortem on all three lambs and they found several plant leaves, which they identified as ivy (Hedera helix) and the laurel-like ornamental shrubs Euonymus japonicus and Pieris japonicus.

The post mortem found their lungs were filled with fluid, haemorrhages on the outer surfaces of their hearts and froth in the tracheas.

There were also haemorrhages along the small and large intestines of one of the lambs.

Reporting their findings in the monthly laboratory report, the vets concluded that the lambs had died from plant poisoning, with the common garden shrubs E japonicus and P japonicus identified as the toxic plants involved.

Poisoning signs and advice

The vets reported that poisoning incidents in sheep can arise when sheep break out into gardens and tend to increase over the winter months, possibly when grazing is limited.

Pieris species are very toxic to both animals and humans due to grayanotoxins that bind to sodium channels of cardiac and skeletal muscle and nerve cells.

The toxic dose of fresh leaves is reported to be 0.1% to 0.6% of bodyweight for ruminants, equating to around 30g to 180g of fresh leaves for a 30kg lamb.

The symptoms of E japonicus poisoning occur eight to 15 hours after intake and include vomiting, abdominal pain, inflammation of the intestines, severe, slimy, watery or bloody diarrhoea, disturbances of circulation, collapse and coma.

Most farmers are unaware that ivy is mildly toxic to ruminants, but to a much lesser degree than the other plants detected, and animals rarely consume enough to do any more harm than a mild, self-limiting diarrhoea.