Download Poisonous Plants - The Parks Trust

Poisonous Plants
This is not a comprehensive list but does outline some of the main plants that should be removed
from pony paddocks in the Milton Keynes area.
Black Bryony (Tamus)
Low Risk
Symptoms:
Severe abdominal pains, decreased appetite, high temperature and profuse sweating.
Notes:
Some reported cases of fatal equine poisoning.
Box (Buxus sempervirens)
High Risk
Symptoms:
Diarrhoea, lack of coordination, convulsions and coma. Respiratory failure is the usual cause
of death.
Notes:
Box hedge has a nasty odour when bitten, either from the plant or by clippings.
Buttercup (Ranunculus acris)
Low Risk
Symptoms:
Salivation, inflammation of the mouth, blisters and abdominal pain with convulsions and colic
usually preceding death.
Notes:
Non toxic when dried. Buttercup has an acrid burning taste that makes them repulsive. Few
reported cases of equine poisoning have been reported as horses normally avoid them.
Buttercups are very invasive, thrive in poor soil and are a common sight in summer. They can
be killed by spraying (followed by at least two weeks rest).
Clover (Trifolium spp)
Symptoms:
Can be associated with laminitis, blood disorders and photosensitivity.
Notes:
Few reported British cases of poisoning.
Foxglove (Digitalis purpurea)
Low Risk
High Risk
Symptoms:
Diarrhoea, abdominal pain, irregular pulse, convulsions and tremors.
Notes:
Not normally eaten as it has a nasty taste but animals can develop a craving for it once eaten.
Does not lose its toxicity when it is dried.
Horsetail (Equisetum spp)
High Risk
Symptoms:
Lack of coordination, pronounced heartbeat after mild exercise, muscle tremors and possible
kidney damage. If untreated this is followed by convulsions and death.
Notes:
Common cause of serious or fatal poisoning in horses.
Laburnum (Laburnum anagyroides)
High Risk
Symptoms:
Abdominal pain, an elevated temperature, tremors, an unsteady gate and convulsions.
Notes:
Fatal poisoning in horses has been reported, mostly involving high consumption of seeds and
pods but nearly the entire tree is poisonous including the bark and leaves.
Deadly nightshade (Solanum nigrum)
High Risk
Symptoms:
Severe abdominal discomfort, staggering and depression.
Notes:
Plant can be found in hedges and wood clearings. Varies in toxicity according to several
factors e.g. climate, season and soil type however there are few reports of poisoning in Britain.
Oak (Quercus spp)
Low Risk
Symptoms:
Lack of appetite, poor coat, constipation followed by diarrhoea which may be blood stained,
abdominal pain, depression, blood in urine. The kidneys can be damaged in extreme cases.
Notes:
Reports of horses eating acorns with little effect, but fatalities have occurred after eating
acorns and other parts of the tree including leaves. Reports of poisoning are common in the
autumn when acorns are more abundant. Rake and remove any acorns.
Potato (Solanum tuberosum)
High Risk
Symptoms:
Salivation, diarrhea, colic, thirst, weakness pulse, circulatory failure, lack of coordination and
convulsions. Coma and death may follow.
Notes:
When potatoes are green and sprouting they contain high amounts of poison which is
destroyed by cooking. Fatalities in horses have been reported.
Privet (Ligustrum spp)
High Risk
Symptoms:
Staggering, intestinal disruption, paralysis, rapid pulse and dilated pupils.
Notes:
Fatal cases of poisoning in horses have been reported with death occurring from 4-48 hours
after ingestion. Most cases involve garden hedges or trimmings.
Ragwort (Senecio Jacobaea)
High Risk
Symptoms:
Weight loss, poor coat, staggering gait, impaired vision, inability to swallow and paralysis.
Symptoms may not appear for several weeks or months but can appear immediately ingested.
Notes:
Highly poisonous and every horse owner's nightmare is digging out this persistent yellow
flowering plant. One of the biggest problems with ragwort is that it is still just as toxic when it
has been dried so can appear in hay. The symptoms can take many weeks or even years to
show. Plant should be pulled out, uprooted and burnt. Always wear gloves.
St Johns Wort (Hypericum perforatum)
Low Risk
Symptoms:
Photo-sensitisation in unpigmented skin which may develop small lesions on its surface;
infection may set in; loss of appetite, weakness, staggering gait and coma.
Notes:
Low level poisoning in horses is probably more common in Britain than realised with some
severe cases. The plant loses 80% of its toxicity when dried but can still be dangerous in hay.
Yew (Taxus baccata)
High Risk
Symptoms:
Lack of coordination, coldness, rapid then weak pulse, excitability preceded by collapse.
Sudden death can occur a few hours after ingestion without any symptoms.
Notes:
Yew is one of the very few poisonous plants that animals will eat voluntarily. All parts are
potentially poisonous. Many cases of poisoning in horses are known – animals dying a few
hours after eating it.