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Below is a list of contents to help you move around the Poisonous Plants information:
Purpose
The purpose of this web page is to advise Surrey's horse and pony owners about some of the most commonly found poisonous plants in the County, how to deal with them safely and where to find further information. Surrey is a beautiful County, with over 25% having been designated as the Surrey Hills Area of Outstanding Natural Beauty, and a further proportion of the County designated for nature conservation reasons.Horses and ponies can have an effect on the landscape, and it is up to their owners and keepers to ensure that this effect is a positive one!
Introduction
Some people consider that everything growing in their paddock except grass is a weed! A lot of plants are really classified as herbs, many of which are not only extremely palatable to horses and ponies, but also beneficial. Herbs are being used far more often in the sacks of horse feed that we buy.
However, some plants – herbs, trees and bushes, are very, very poisonous. There are stories of horses dying with their mouths still full of the piece of yew tree they were just eating! Many of these poisonous plants are harmful to humans as well, so care must be taken when dealing with such plants. Wherever possible, 'blanket' spraying by a chemical contractor should be avoided as this can have disastrous effects on other wild plants. Many plants that are common in old meadows provide extremely important habitats for insects and birds, providing feeding and nesting places that are often not found elsewhere.
Whilst there are probably hundreds of plants that may cause harm to horses, only the most common can be described here, and it is up to the horse and pony owner to ensure that they protect their animals from the risk of eating them.
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Welfare
The welfare of horses and ponies must be the primary consideration.
Generally, horses and ponies are selective grazers and will not eat anything that is unpalatable. The danger is when they become really hungry and will eat just about anything. This is why it is important not to overstock your land. Hay, as well as pasture, can also be a risk for horses. Some plants, such as highly toxic ragwort (Senecio spp), remain poisonous but can become palatable when dried and baled into hay. It is important to always buy hay from a reputable merchant who is aware of the potential danger of poisonous plants in their hay.
Boundaries with gardens and allotments must be kept well maintained and horses and ponies must be prevented from leaning over fences to reach plants on other peoples' land. It is also important that neighbouring gardeners and allotment holders don't put weeds, prunings, grass clippings and other garden waste where horses and ponies can reach them. Well meaning neighbours often think they are being kind but have not had the potentially disastrous results of their actions explained to them!
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Poisonous Plants
Good fencing and fencing out trees and hedges is a really good way of ensuring your horse or pony is safe from accidental poisoning. The webpage entitled
Trees and Hedges Advice has useful information on how to protect trees and hedges from being eaten by horses and ponies, and how to protect your horse or pony from being poisoned!
The following is a list of some of the most common poisonous plants that you may come across in Surrey:
Bracken (Pteridium aquilinum) and Horsetail (Equisetum spp)
Bracken and Horsetail are both poisonous plants that can be hard to control. Whilst not particularly palatable, they are often eaten when there is no other food available, and are most dangerous when in hay, when like ragwort, they remain highly toxic.
Continual mowing throughout the growing season will gradually weaken the plants, which will eventually die. Chemical control may be necessary on large areas where the mowing regime is not practicable.
Buttercups (Ranunculus spp)
Buttercups are potentially harmful as they contain a compound that causes inflammation and ulceration of the mouth. Horses and ponies which eat too many buttercups may get colic, but more usually stop eating the buttercups when they become ill, before the consequences are fatal. Creeping buttercup is the species found most often in improved paddocks. The drying process breaks down the harmful compound, so the plant is not dangerous in hay. Unfortunately it is hard to reduce the number of buttercups in fields without applying herbicide,
as they grow close to the ground and are not killed by repeated mowing. Buttercups are often indicators of damp and fertile or slightly acidic soil, often worsened by overgrazing and 'poaching'. Where appropriate, a dressing of lime may allow the grasses to overwhelm the buttercups. Cross grazing, maintaining drainage and harrowing may also help. Good grassland management, particularly ensuring that fields aren't overgrazed
, is the cheapest and most natural method of control.
Common Privet (Ligustrum spp)
Common Privet is often present in hedges of garden and paddock boundaries
. As this is a potentially lethal plant, it is important to make sure that horses and ponies stretching over their fences cannot reach it. It is also important to explain the risk of privet poisoning to the hedge owner so that they do not leave any clippings or prunings where they can be reached.
Foxglove (Digitalis purpurea) and nightshade (Atropa belladonna/solanum spp)
Foxglove and nightshade are woodland edge plants that are often found alongside hedges. Deadly nightshade can be distinguished from woody nightshade when it bears berries, as these are black, rather than red. Whilst neither plant is generally lethal, both cause unpleasant reactions in horses and should be controlled where they are found. This is easily done by hand pulling, ensuring that gloves are worn.
Oak trees (Quercus ssp.)
Oak trees can poison animals that ingest their acorns. Eating acorns can lead to stomach impaction, colic and even death. It has also been known to cause laminitis.
On the New Forest in Hampshire, pigs were traditionally turned onto the Forest in the autumn to eat the acorns and protect the cattle and ponies from the risk.
The best prevention is to collect up the acorns and dispose of them safely.
Ragwort (Senecio spp)
Sometimes known as 'Staggerweed' is probably one of the most easily identified and most talked about poisonous plants thanks to the important and effective campaigns mounted by the British Horse Society (BHS).
Ragwort is widely accepted to be the cause of more livestock deaths than any other plant. It is defined as an 'injurious weed' in the Weeds Act 1959. The Ragwort Control Act came into force in 2004. Amending the Weed Act, it provides added protection to horses and allowed for the production of a Code of Practice on How to Prevent the Spread of Ragwort and the supplementary Guidance on the Disposal Options for Common Ragwort. Both are recommended reading for horse-keepers. The Department for Environment, Food & Rural Affairs (Defra) can take enforcement action requiring an occupier of land on which ragwort is growing to take action to prevent the weed from spreading onto land used for grazing, forage production or other agricultural activities.
The plant is generally identified by its densely packed, flat heads of daisy like clusters of yellow flowers which mature into hundreds, if not thousands of downy, white seeds. These seeds are quickly and efficiently airborne and carried by the wind rapidly spreading the problem. Knowing how to identify Ragwort is of primary importance, as not all yellow flowering plants are poisonous!
Once correctly identified, ragwort must be carefully removed and disposed of. Ideally it will be hand pulled or dug up (wearing protective clothing), ensuring that all the roots are removed. Where the site is too large, unfortunately herbicide control may be necessary but the timing is crucial to maximise effectiveness: refer to manufacturers guidelines. Chemical treatment must be in the autumn to treat the plant if the field is to be used for hay the following year, otherwise there is a risk of the dead plant being baled and poisoning the eater. Ragwort remains toxic when treated, wilted, cut or pulled but becomes more palatable so horses must not have access to ragwort whether it is fresh, treated or removed from the ground.
Cutting will not prevent regrowth and will turn the plant from a biennial into an annual. To reduce the inadvertent spreading of seeds, whenever practicable, ragwort should be disposed of on site. Please refer to the Ragwort webpage for detailed information about the plant.
Yew trees (Taxus baccata)
Yew trees are traditionally grown in and around churches. They often do grow in other locations, and are particularly associated with the chalk downlands around Surrey's Box Hill. They are never used for hedging where any livestock are kept, as they are so very poisonous. But they do make a beautiful evergreen garden hedge, so it is important to make sure that they cannot be reached by horses and ponies stretching over their fences. It is important to explain the risk from yew to the tree or hedge owners so that they do not leave any clippings or prunings where your animals can reach them.
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Poison from verges
Whilst horses seem to be less susceptible to lead poisoning than ruminants, the toxicity is cumulative and inhalation as well as ingestion may increase uptake of this harmful metal. Herbage sampling alongside major trunk roads in the USA has revealed worrying amounts of environmental lead contamination. In some cases, lead investigation may, therefore, be warranted in horses showing weight loss when grazing pastures alongside motorways or busy roads. It is always worth having the pasture tested if you suspect it may have been exposed to toxic substances.
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How to keep horses safe from poisoning:
- Avoid overgrazing and carry out year-round management to encourage a dense sward of grass to minimise opportunistic weed growth.
- Pull out ragwort (including the roots) and other poisonous plants and dispose of carefully. Rake up and remove any acorns.
- Where herbicide application must be undertaken, try to just 'spot treat' problem areas to protect other wildlife and plant species.
- Check your boundaries for evidence of poisonous plants, making sure you go well into the depth of hedges, and a metre or so to the other side of post-and-rail fences.
- Make doubly sure that boundaries with gardens and allotments are horse proof and that neighbours are aware of the risks to your animals from their plants.
- Break open hay bales to look for dried plants and discard any you cannot readily recognise, and make sure your hay merchant is reputable.
- Horses, ponies and donkeys will be far more likely to eat poisonous plants when they have nothing else on offer –so beware of overgrazing
- Unfortunately, some plants become more palatable when they have been treated with herbicides so always ensure that you follow the manufacturer's guidelines as to how long to keep animals off the pasture after treatment.
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Summary
It is the horse and pony owner's duty to ensure that their animals are protected from poisonous plants by their own vigilance. It is only really necessary to treat and remove those plants which pose a risk to animals. Paddocks and fields should be frequently walked to make sure that they are free from harmful plants, and good basic plant identification skills should be learnt. Fences should be regularly checked to ensure that they not only prevent animals from straying, but also protect them from poisoning themselves by eating harmful plants. Good relations with your neighbours are important for many reasons, not least to make certain that they are aware of the risks to your animals from garden plants!
