Toxic Plants for Horses: Recognising and Preventing Poisoning
Many common plants and trees can be toxic to your horse. As owners it is important that we are able to recognise these plants and take measures to prevent accidental ingestion and poisoning. Some of the most common plants that are toxic to horses include:
RagwortRagwort is a flowering plant that can be identified by its bright yellow flowers, which have 13 petals and are arranged in clusters. The leaves of the plant are deeply divided and are a distinctive shade of green. Ragwort can grow up to 1.5 meters in height and is usually found in open fields and along roadsides.
ButtercupButtercup is a flowering plant that can be recognised by its bright yellow and shiny petals that resemble small cups. It has glossy, dark green leaves and typically grows low to the ground. Buttercup comes in various species and can grow up to 60cm in height.
FoxgloveFoxglove is a tall flowering plant with bell-shaped flowers that are typically pink or purple in colour. The plant can grow up to 1.5 meters in height and has large dark green leaves that usually have a hairy texture.
Deadly NightshadeDeadly Nightshade is a small shrub with shiny, oval-shaped leaves that are a dark green colour. The plant produces bell-shaped flowers that are a purplish-brown colour and are followed by shiny black berries. It is often found in woodlands, hedgerows and other shaded areas.
LaburnumLaburnum is a deciduous shrub that can grow up to seven meters tall. It has compound leaves and bright yellow flowers that hang in long clusters. The flowers bloom in late spring to early summer and are followed by poisonous seed pods.
BrackenBracken is a fern with large, triangular leaves that grow up to 6 feet tall. The fronds have smaller, feathery leaflets that are dark green on top and lighter green underneath.
OakOak trees are large and sturdy, reaching up to 100 feet tall with a broad, rounded crown. Oak leaves are large and broad with a glossy dark green surface that turns brown, red or orange in Autumn. Acorns, the small, round nuts produced by oak trees, are brown and found attached to a cupule.
YewYew is an evergreen tree that has distinct needle like leaves. Yew trees also possess bright red berries and small red or purple coloured flowers that bloom in the Spring.
PrivetPrivet is an evergreen shrub with small, oval-shaped leaves and small, white, sweet-smelling flowers that bloom in the summer.
RhododendronsRhododendrons are evergreen shrubs with glossy leaves and showy, trumpet-shaped flowers that come in various colours including pink, red, purple, white, and yellow.
SycamoreSycamore is a deciduous tree with a broad canopy and thick branches that can grow up to 35 metres tall. It has large, bright green, palmate leaves that turn yellow or brown in Autumn. The sycamore tree produces narrow V shaped winged seeds that are commonly known as helicopters. These seeds can be dispersed great distances in windy conditions.
IvyIvy is an evergreen climbing plant that can grow up to 30 meters tall. Ivy is an invasive plant that can often be found clinging to the branches of other trees. Ivy leaves are typically dark green, glossy, and have a distinct heart shape, with three to five pointed lobes. In late Summer and Autumn, ivy will produce small, greenish-yellow flowers which are followed by black or dark purple berries.
Symptoms of Poisoning From Plants in Horses
Symptoms and their severity will differ depending on what type of plant and the quantity your horse has consumed. Some symptoms of poisoning in horses include:
- Behavioural changes
- Dullness & lethargy
- Breathing difficulties
- Inability to swallow (ataxia)
- Tremors and convulsions
- Inability to stand
- Dilated pupils
What to do if you think your horse has eaten a poisonous plant?
In any cases of suspected poisoning or ingestion of noxious plants, it is important to contact a vet as soon as possible. If possible, tell your vet the type of plant you suspect your horse has eaten and the quantity. This will help the vet to make more informed choices regarding a treatment plan. Treatment will depend on the type of plant and the quantity consumed.
Anti-toxins are available for many toxins however some toxins such as Hypoglycin A, which is found in sycamore seeds, do not have a known anti-toxin which makes treatment a lot more difficult. Intravenous fluids and anti-inflammatory drugs can also be prescribed to help manage symptoms.
More severe cases of poisoning may require intensive round the clock veterinary care which is usually carried out at a specialist veterinary hospital. The chances of survival are greater if treatment is commenced sooner. Some toxins can cause fatalities in as little as four hours post consumption therefore it is extremely important that a vet is contacted as soon as possible in any cases of suspected poisoning.
There are several preventative measures horse owners can take to minimise the risk of poisoning, these include:
Checking paddocks on a daily basis to ensure there are no signs of poisonous plants. If there are any poisonous plants present it is important that these are removed and disposed off in an appropriate manner. It is important that dead plants are not left in paddocks, as plants ferment and sugar is released, meaning plants that were once bitter will become sweeter and much more appealing to horses. If it is not possible to remove poisonous trees or plants from paddocks, these should be fenced off so horses can not have direct access to them. When out hacking it is a good idea to prevent your horse from grazing unknown bushes and hedgerows as this is where many poisonous plants will grow.
Care should be taken if spraying paddocks to get rid of unwanted vegetation as many herbicides are also toxic to horses. It is important to remove horses from a paddock for a period of time following herbicide application. The length of time will depend on the type of herbicide used. Always refer to the herbicide manufacturer if you have any doubts regarding its safety for use in horse paddocks.
Regular paddock maintenance should also minimise the risk of poisoning. Invasive plants such as ragwort tend to favour ground with poor soil quality. Year round owners should aim to keep stocking densities in paddocks low as this will prevent them from becoming overgrazed and reduce the likelihood of the ground becoming poached. Regular poo picking should be carried out as horses will tend not to graze areas of paddocks that are covered in droppings, meaning invasive plants and weeds are more likely to grow. Harrowing paddocks is also a very efficient means of breaking up droppings and destroying the roots of invasive plants over larger surface areas.
Horses are much less likely to consume poisonous plants if their appetite needs are being met. As a minimum horses should be consuming two percent of their body weight daily, with a minimum of 1.5% of their body weight being fed as forage on a dry matter basis. If your horse is still out grazing during the Autumn and Winter months it is important to provide them with supplementary forage as the grass at this time of year will have a much lower nutrient content.
It is crucial for horse owners to educate themselves on the types of poisonous plants that are commonly found in pastures as this will allow them to effectively manage their ground for safe grazing year round.