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DANGER!! - Poisonous Plants for Horses

WATCH OUT! Pretty flowers with a deadly altar ego. Poisonous plants for horses.
The growing season is in full swing and the country side is in full bloom, however some of the plants you will see are very toxic to your horse and you need to be able to indentified and eradicated them from your pasture.
As in humans the horse liver is a vital organ to filter the good from the bad of ingested foods. In a horse the liver is the largest gland weighing approximately 5 kilos and is responsible for detoxifying and removing harmful waste products from the body in the form of urea.

Fortunately the liver has a remarkable ability to regenerate however with persistant bombardment of toxins such as the ones listed below the proteins that it needs to do this are compromised and therefore the liver cells die and form fibrous tissues. Should the liver become reduced to about 30% of its function, serious signs of liver damage will become apparent often devastating results, this can happen over many years so vigilance is critical.

Sycamore Check for sycamore trees near and in your pasture and grazing
During spring and autumn horses will eat the tree's so-called helicopter seeds and leaves when other sources of food are meager.The helicopter-like seeds contain toxins linked to atypical myopathy. A study carried out by Faculty of Veterinary Medicine at the University of Liege, Belgium, linked toxins from sycamore tree seeds to the fatal condition, which causes substantial muscle damage and in 75 per cent of cases death within 72 hours.  Symptoms include dark coloured urine, muscle stiffness unrelated to exercise, muscle tremors, lethargy and colic like symptoms.

The most common know plant is
ragwort rosette
The early stages of its growth is a rosette habit similar to a young dandelion however it grows quickly into the more familiar yellow plant as pictured below.

The alkaloid toxins that it produces, causes the liver cells to expand and eventually die, the subsequent prolonged ingestion of this plant on the liver is increasingly compromised.

It is estimated that up to 150,000 seeds are carried in one ragwort flower which can travel airborne for up to 40 metres, therefore any plants you find in your pasture or any neighbouring areas should be dug out and burnt, preferably before the flower head seeds.

Always use gloves to pull the plants and dispose of them in a safe area, remembering they can still be damaging when cut or harvested as part of hay or haylage.

Buttercups, which are a paddock owners nightmare especially if left untreated year after year can be another danger.

Fortunatley horses will not eat buttercups if there is suffieint grass however if a large number are consumed symptoms of irritaion of the mouth, colic and diarrhoea will become evident.

Not only does this small plant spread and restrict grass growth they contain a toxin which cause's blistering in the mucous membrane lining of the entire gastrointestinal tract and consequently the liver can be affected. 
The earlier articles on paddock maintenance discussed the spraying times to eradicate buttercups in early spring however a licensed spray contractor will always advise as to when they can be treated.

It is well to note that once cut and dried they are no threat therefore frequent topping is essential.
Centuries ago, our beautiful island was mostly woodland therefore the presence of the Bracken Fern is still widespread especially in well drained soil, in ditches, along wooded areas and in run down pastures.

The horse may nibble braken fern if there is a shortage of good grass. It is highly toxic and can cause your horse a lot of discomfort portrayed in an unsteady gait, constipation, thick mucous and high sensitivity.
Bracken fern must be removed,  remembering that even if cut or strimmed  and left lying around it is still highly toxic. 

or scouring rush is often found in marshy pasture or alongside a brook or stream. This contains the same damaging contaminate as bracken fern which again when cut into a hay mix retains it's toxicity. An added problem here is that it stays green in the winter which may encourage the horse to nibble if no alternative is available.
Deadly night shade
betterdeadly nightshade
 Deadly night shade is a creeping vine type plant which inhabits edges of fields in the hedges and along fence lines.

Although it has a very attractive flower it is very toxic to your horse and if left untreated continuous ingestion can lead to death.

poison hemlock1
Poison hemlock has a much broader leaf than the very common cow parsley which you may know. It is particularly virulent on roadside verges and if ingested can poison your horse.

Early signs of your horse ingesting this weed are frothing of the mouth, tightly clasped jaw, nervousness and a weak but rapid pulse.

General Signs of poisoning can be indicated by: 
Excessive saliva production - dribbling
NOTE: If you discover your horse is suffering from the above remove the frothy saliva and any waste food stuff from within the mouth, thoroughly rinse out the cheeks, lips and mouth area with warm water and a sponge.  Eventually the horse will relax the jaw and then they must be encouraged to drink and eat a little hay.  
Lethargy, yawning, head pressing and dullness.
Unco-ordinated movement and general confusion.

Symptoms of Liver Damage can be indicated by:
  • Diarrhoea or constipation.
  • Weight loss
  • Poor performance.
  • Excessive sun burn in low pigmented areas.
  • Jaundice - shown in the membrane around the eye becoming yellow.
  • Swelling under the belly and in hind limbs.
You must consult your vet immediately if you have any concerns or identify any of the above  symptoms.

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