Watch Your Hedges and Ditches: The Hidden Danger of Hemlock

Hemlock flower.

As the seasons shift and the landscape dries out, it’s worth taking a moment to look a little closer at your hedgerows and ditches. You might be surprised—or alarmed—by what’s growing there.

Recently, there’s been a spike in coverage across farming media and social platforms about Hemlock poisoning. It’s not just a headline-grabber; it’s a real and devastating issue. Around the same time as one widely reported case, our own post-mortem room in Dumfries saw a similar incident. The diagnosis was straightforward: group history and the presence of partially chewed Hemlock roots in the rumen told the story.

Why now?

Dry summers can push livestock to forage more aggressively, especially in areas they might normally avoid. Ditches, often overlooked, become more accessible when water levels drop. After heavy rain, roots and plants may be more exposed—making them easy pickings for curious cattle and sheep.

Earlier this year, our colleague Lorna Galloway from SAC Consulting wrote a detailed article on Hemlock poisoning, prompted by cases in outwintered cattle. With ditches again playing a role, we felt it was important to reshare this information with vets, farmers, and anyone managing land with livestock.

Meet Hemlock: A Silent Killer

Hemlock (also known as dead man’s fingers, water dropwort, or poison hemlock) is a highly toxic plant to both humans and animals. It’s part of the carrot family, which means it can easily be mistaken for cow parsley or wild carrot. But there are key differences:

• Smell: Hemlock has a distinctive, unpleasant mousy odour.
• Appearance: Look for purple blotches on its hairless stems and white lacy flowerheads.
• Habitat: It thrives in undisturbed soils—think wastelands, roadsides, ditches, and waterways.

What Makes It So Dangerous?

Hemlock contains coniine and other toxic alkaloids. The roots and seeds are especially potent. Ingesting the plant can lead to:

• Shallow, rapid breathing
• Salivation
• Teeth grinding
• Diarrhoea
• Convulsions
• Paralysis
• Sudden death

Animals may appear uncoordinated and, alarmingly, some return to feed on the plant even after initial poisoning.

What Can You Do?

There’s no cure for Hemlock poisoning, though in very mild cases, prompt treatment with laxatives and sedatives has shown some success.

If you spot Hemlock:

• Wear protective clothing when handling it.
• Avoid skin contact and inhalation of plant material.
• Bag and dispose of it safely.
• For larger infestations, herbicide application may be necessary. Products containing Glyphosate have proven effective, but always read and follow the label instructions carefully.

Stay vigilant. A quick walk around your fields and ditches could save lives—both animal and human. If you’re unsure about plant identification or need advice on removal, reach out to your local SAC Consulting team or vet practice.

Posted by SRUC Veterinary Services on 19/09/2025