24/08/2026
This summer has brought with it more than one battle for farmers. As well as Bluetongue Virus, we have also been struck by drought, resulting in many people having to dip into their winter feed.
As well as being concerned about whether our animals have enough to eat, there is another risk to consider. When grass is short, hungry cattle and sheep may begin grazing on bitter or unpalatable plants that they would normally ignore, some of which can be highly toxic - But are you confident identifying them?
In Cornwall, some of the toxic plants we may encounter include:
🌱 Hemlock Water-Dropwort (Oenanthe crocata)
Highly prevalent across West Cornwall along watercourses and ditches. Livestock may venture into boggy areas in search of green growth and bite into the highly toxic roots, also known as “dead man's fingers”. These contain a powerful neurotoxin that attacks the central nervous system.
🌱 Hemlock (Conium maculatum)
Commonly found in Cornish hedgerows and field margins and recognised by its purple-spotted stems. Livestock will often avoid its unpleasant smell when grass is plentiful but may graze it out of desperation. It also contains potent neurotoxins.
🌱 Bracken Fern (Pteridium aquilinum)
Bracken blankets extensive areas of Cornish moorland and rough hill ground. If pasture grass becomes scarce, cattle and sheep may eat the green fronds in summer or rhizomes in winter, potentially causing severe illness, including bone marrow suppression resulting in depleting blood cells.
🌱 Common Ragwort (Jacobaea vulgaris)
Widely seen on dry pasture and coastal clifftops across the county. While generally unpalatable when fresh, a severe lack of grass may push livestock to eat it, potentially leading to irreversible liver damage.
🌱 Foxglove (Digitalis purpurea)
A familiar native wildflower found in Cornish hedgerows, woods and banks. While incredibly bitter, desperate livestock may take a bite, introducing potentially lethal cardiac glycosides into their system.
🌱 Rhododendron (Rhododendron ponticum)
Often spreads into pastures from old Cornish country estate gardens or woodland margins. It remains green year-round, which can make it tempting to hungry livestock when fields turn brown. As well as causing neurological and cardiovascular signs, rhododendron is the only cause of true vomiting in ruminants.
🌱 Oak (Quercus spp.)
Found along old hedgerows and wooded borders. Hungry livestock may seek out fallen leaves and green acorns, which can cause severe kidney damage.
Signs to look out for include:
⚠️ Excessive drooling: Heavy salivation or frothing.
⚠️ Digestive upset: Severe diarrhoea (sometimes bloody), abdominal pain, bloating or unusual vomiting.
⚠️ Neurological distress: Muscle tremors, staggering, incoordination (ataxia), head pressing or seizures.
⚠️ Breathing difficulties: Shortness of breath, rapid breathing, gasping or respiratory paralysis.
⚠️ Unexplained sudden death.
🚨 If you notice any combination of these signs, please remove all animals from the current grazing and give us a call immediately.
With grass becoming increasingly scarce, now is a good time to take a careful look around your fields, hedgerows and boundaries. Being able to identify potentially toxic plants could make all the difference. 🐄🐑🌿
