In mid-October we were called to examine two 14 month-old beef heifers which had exhibited a sudden onset of foul smelling diarrhoea, inappetence and abdominal pain whilst at grass. Despite symptomatic treatment both animals died within 48 hours. Faecal samples were analysed at the practice but did not reveal a significant parasite burden. One heifer was submitted to the laboratory for a full post mortem investigation.

The post mortem revealed significant kidney damage which raised suspicion of the ingestion of a poisonous substance. On further investigation the field in which the heifers were grazed had 3 oak trees and an abundance of acorns. Acorns contain high levels of tannins which cause acute kidney damage.

Cattle and sheep can exhibit clinical signs of foul-smelling diarrhoea which may contain blood, weakness, inappetence, weight loss and may appear hunched up due to abdominal pain. They may die relatively suddenly. Those animals which survive exhibit weight loss and anaemia as the result of kidney failure.

It is advisable to prevent stock having access to acorns by removing them from fields with oak trees in the autumn or erecting a temporary electric fence. Stock are more likely to ingest acorns if grazing is in short supply.

Interestingly one of the laboratories that we use has reported over 20 cases of acorn toxicity this year, in comparison to only one last year.