Just as the heatwave came to an end, it claimed its first victim on the Thrive demonstration farm in Cashel, Co Tipperay, on Sunday.

Throughout the hot spell, cattle had coped well, utilising the abundance of shade available on the farm. Drinking troughs were checked twice daily to ensure cattle were never without water.

On Sunday one bullock presented with what looked like the onset of photosensitisation (sunburn in cattle) around the muzzle. This came as a shock as stock were herded Saturday evening and no sickness was seen.


Farmer John Hally called the vet out immediately and following examination the prognosis was not good. The bullock was displaying signs of heatstroke as well as photosensitisation, which can be caused by the ingestion of a plant containing photochemical agents.

Plants such as St John’s Wort and Bog Asphodel are known to cause the issue – both of which can be identified by them having a bright yellow flower.

The vet also noted the enlargement of the liver area which again can be a symptom of photosensitisation. Despite the efforts of both John and the vet, the bullock was dead within a couple of hours.

This bullock had been seen by the vet earlier in the summer as he was staying away from the grazing group and lying on his own quite a lot. He seemed stiff in his back legs at times also. The vet put this down to arthritis in the joints.


This condition probably did not help the bullock during the hot weather. Where the other cattle moved around the field each day to follow the shaded areas, this bullock spent a lot of time lying next to the drinking trough.

He had been thriving and putting on weight up to this point, and before Sunday was displaying no signs of sickness.

It is always unfortunate losing an animal. But when they are within six weeks of being finished it can be extra frustrating. Thankfully the rest of the 140 finishing cattle and 150 calves are all in good health and doing well.

All stock will be weighed at the end of this week and there will be an update in the Irish Farmers Journal next week.