This autumn, vets across the UK are reporting an increase in cases of acorn poisoning in cattle and sheep, with several confirmed diagnoses from laboratories. The Animal & Plant Health Agency (APHA) has highlighted the problem via the Emerging & Endemic Disease Alert System (EEDAS).
2025 has been described as a mast year. When oak trees produce an unusually high number of acorns. Combined with stormy weather bringing down large quantities at once, livestock are at greater risk of exposure.
Green acorns contain high levels of tannins, which are toxic to ruminants. Ingestion damages the kidneys and gastrointestinal tract, leading to severe illness and potentially death.
Symptoms usually develop 3–7 days after ingestion and can include:
> Loss of appetite and depression
> Excessive drinking and urination
> Blood in urine
> Yellowing of mucous membranes (jaundice)
> Constipation followed by diarrhoea
Diagnosis is usually based on clinical signs, blood tests (showing kidney damage), post-mortem findings, and known grazing exposure. Unfortunately, mortality rates can be high once poisoning occurs.
Check fields daily for fallen acorns, especially after storms.
Move livestock away from areas with oak trees if acorn fall is heavy.
Provide alternative forage to reduce the risk of stock consuming acorns out of hunger.
For more detailed information: MSD Veterinary Manual – Quercus Poisoning in Animals
If you’re concerned about possible acorn poisoning in your herd or flock, contact your vet immediately. Early action can save lives.
Marketing Executive
