Alezane's World of Horses - Horse Wise

Poisonous Plants

Ragwortragwort rossettes
Young plants of common ragwort are evident from the autumn to early June as low rosettes in pasture and on bare ground. The leaves of these young plants are extremely variable, either undivided or simply divided into terminal oval and smaller lateral lobes. These are usually a deep bottle-green, tinged purple, and slightly glossy on the upper surface.

In their second or subsequent years the rosettes mature and produce flowering stems from late June onwards. These are between 30-100cm tall, carrying dense flat topped clusters of bright yellow daisy-like flower heads each 1.5-2.5cm across. The leaves on mature plants are strongly divided into narrow lobes with the bases clasping the non-woody main stem. The flowering stems die back afterproducing seeds.

There are four different species of Ragwort:
Common Ragwort (Senecio Jacobaea) - the most widespread type of Ragwort.
Oxford Ragwort (Senecio squalidus) - common in waste places and dry pasture.
Hoary Ragwort (Senecio erucifolius) - dry pasture weed.
Marsh Ragwort (Senecio aquaticus) - found in wet meadows, moorland pasture, ditches and marshes.

Ragwort is normally a biennial (rosette - spring 1st year; flowering - July/August 2nd year).
Its seeds can be dormant in the soil for up to 20 years.
Each plant can produce up to 150,000 seeds with a 70% germination rate
Ragwort flourishes on neglected or overgrazed pastures but will not establish where there is a vigorous, dense growth of grass.

How to complain about the spread of Ragwort - DEFRA offers the following advice ....

If you are concerned about Ragwort or other injurious weeds spreading to your land, you must first approach the owner/ occupier of the land on which the weeds are growing and ask them to take steps to clear the weeds. In the vast majority of cases the owner/ occupier of the land will normally react positively.
In the case of Ragwort or other injurious weeds growing alongside the motorway or trunk roads, the complaint should be referred to the Highways Agency, and for minor roads, the local highway authority. Where Ragwort is growing on railway land and embankments, Network Rail should be contacted. The telephone numbers for the Highways Agency and Network Rail are:

Highways Agency: Tel: 08457 50 40 30 - (Motorways and trunk roads)
Network Rail: Tel: 08457 11 41 41 - (Railway land and embankments)

For all other roads Contact the Local Highways Authority. For contact details see the local telephone directory or the local authority website.

If this approach does not resolve the problem, you should complete a Weeds Act complaint form (Weed 2 Rev 7/03). Hard copies can be obtained from the Rural Development Service offices at Bristol or Crewe as appropriate.Before completing the form, please read the accompanying guidance note. The completed form should be returned to either the Bristol or Crewe Rural Development Service office.

The contact details for the Bristol and Crewe offices, and the areas covered by each office, are set out below .

Bristol - South West Rural Development Service
Block 3
Government Buildings
Burghill Road
BS10 6NJ
Tel: 0117 959 8622

Areas covered: Bedfordshire, Berkshire, Buckinghamshire, Cambridgeshire, Cornwall, Devon, Dorset, East Sussex, Essex, Gloucestershire, Hampshire, Hereford & Worcester, Hertfordshire, Isle of Wight, Isles of Scilly, Kent, London Boroughs, Norfolk, Oxfordshire, Shropshire, Somerset, Staffordshire, Suffolk, Surrey, Warwickshire, West Midlands, West Sussex, Wiltshire.

Crewe - North West Rural Development Service Office Defra
Electra Way
Tel: 01270 754262

Areas covered: Cheshire, Cleveland, Cumbria, Derbyshire, Durham, Greater Manchester, Humberside, Lancashire, Leicestershire, Lincolnshire, Merseyside, North Yorkshire, Northamptonshire, Northumberland, Nottinghamshire, South Yorkshire, Tyne and Wear, West Yorkshire.


Bracken is not usually seen in semi-urban areas, but Is increasing in many areas, particularly where hills and banks make cultivation difficult. It spreads from its roots (rhizomes) which are very deep and hard to remove, and is poisonous whether green of dry.When thebracken fronds are emerging heavy harrowing, repeated every three weeks, is a highly effective control measure, but the treatment must be repeated for several years to ensure eradication. By mid-summer, the plant is lush and dense. Repeated cutting can weaken it and expose the root system to frost damage in winter. Burning off, where safe, in the autumn has the same effect. A specialist spray is available but requires expert application.

Removing horses from bracken infested pasture may not halt the onset of disease. Weight loss may be the first symptom, followed by weakness and abnormalities of gait. The horse may stand with its back arched and legs far apart, and stagger if forced to move. In the early stages a slow abnormal heart rhythm may be symptomatic. Death will usually occur within 10 days of the onset of symptoms. Horses can be treated with thiamine injections if diagnosed quickly.Horsetail and groundsel
- commonly found in fields and roadsides, causes similar illness.
- frequently found in grazing land (and a symptom of excess acidity) contain acompound which can cause inflammation or ulceration of the mouth, and can lead to colic. The horse normally avoids them.


- can cause diarrhoea, abdominal pain, tremors and convulsions. It is normally only                      eaten if found in hay.

Potato - although widely used to feed cattle and pigs, green potato tubers contain solanine, and the horse is much more vulnerable to this type of poisoning. Symptoms include salivation, diarrhoea, colic, thirst, weakness, and paralysis.

St John's Wort

Common Dt. John's WortSores caused by St John's Wood

causes photosensitation in areas of un pigmented skin, which can become red and irritated when exposed to sunlight. When dried, it is far less toxic but is still poisonous when found in hay.


Deadly Nightshade

deadly nightshade
- this plant is normally found in hedges and wood clearings. Typical symptoms include dilated pupils and an inability to stand, although it is not normally fatal.

- fortunately, the yew tree is not common, because it is deadly to horses and causes such rapid death that horses have been found with the leaves still in their mouths.This list is far from exhaustive - there are dozens (if not hundreds) of other plants and weeds that will cause illness - at least - if eaten by horses.
The golden rule for the horse owner is to be vigilant. If you don't know what it is - find out. If your field borders a garden, ensure the owners / gardener realises that many plants are poisonous and ask them not to drop weeds or prunings where a horse may reach them.
Particular care must be taken in purchasing hay or horsehage.

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