Horses And Poisonous Plants In The Pasture

2023 Author: Molly Page | [email protected]. Last modified: 2023-05-24 12:33

Do you know what grows in the pasture where your horse grazes, besides the harmless grass? Unfamiliar weeds can fill an entire field in one year if a few seeds accidentally enter it. Horses grazing near a forest, road, ornamental hedge, lawn, or garden risk eating a poisonous plant. Pasture is the main source of toxic plants, the second such source is hay.

Fortunately, most horses don't eat poisonous plants because they are tasteless. Moreover, it is very rare for a handful of poisonous grass to be dangerous to the horse's health. The exception is yew and cicuta, which are deadly. But horses rarely have access to these plants. Horses usually eat poisonous plants during drought, when there is little grass in the pastures. They may also engage in eating unfamiliar plants if they are bored.

Do not under any circumstances allow a pregnant mare to eat poisonous plants. The embryo is most vulnerable to toxins during the first trimester of pregnancy, when the foundations of future organs are being laid. A classic example of a horse eating hellebore in early pregnancy is the birth of a foal with one eye. So keep your mares away from pastures with unfamiliar plants.

Treatment usually does not depend on a particular plant. Typically, the veterinarian will offer activated charcoal and intravenous fluids to cleanse the blood.

GASTROINTESTINAL DISEASES

Colic and diarrhea

Various plants can cause these symptoms. The most common culprit is oak (Quercus), which contains tannins. First, the horse's droppings acquire a dark color, then colic and bloody diarrhea occur, the mouth becomes covered with ulcers, and suffocation is observed.

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Other plants that cause colic and diarrhea:

- horse chestnut (Aesculus hippocastanum), - purple bindweed (Ipomaea purpurea), - Datura (Datura), potatoes (Solanum tuberosum), tomato (Solanum lycopersicum), - foxglove (Digitalis), - (Nerium), - Lakonos (Phytolacca), - Coffee sprouts (Coffea) or Senna (Senna), - Buttercup (Ranunculus), - Broad-leaved Calmia (Kalmia latifolia), - Azalea (Azalea) and Rhododendron (Rhododendron), - Privet Lyonia (Lyonia ligustrina), - castor oil plant (Ricinus communis), - white acacia (Robinia pseudoacacia).

When poisoned with certain toxic plants , the horse will experience excessive drooling, indicating difficulty swallowing. The following plants cause these symptoms:

- alfalfa (Medicago) or clover (Trifolium) affected by the fungus, - burdock (Arctium lappa), - ears with spines and thorns, - ears of barley (Hordeum), - prickly pear (Opuntia), - Caroline nightshade (Solanum carolinense), - green feather grass (Stipa), - wheat ears (Triticum), - dioecious nettle (Urtica dioica), - cockle thorns (Agrostemma).

DISEASES OF THE LIVER, JARCUS AND PHOTODERMATITIS

If the horse has died of liver disease, an autopsy should be done to determine the cause of the disease. The toxins in the plant leave marks that help the pathologist distinguish death from plant poisoning from other causes. When the symptoms of liver disease occur in several horses at once, then the root of the problem is definitely to be found in poisoning with poisonous plants.

Some plants contain photodynamic substances that, when consumed, accumulate in the horse's skin. White wool has little protection from the sun, so only those areas of the skin that are covered with white wool are affected. These types of toxins are found in St. John's wort (Hypericum) and buckwheat (Fagopyrum).

Other plants cause liver disease directly, and the accumulation of photodynamic substances is only a secondary effect of liver dysfunction. Plants containing these toxins:

- plantain (of Plantago), - ragwort (Senecio), - amsinskiya (Amsinckia), - wood-mat (Cynoglossum officinale), - plumbago European (Plumbago auriculata), - Heliotrope (Heliotropium), - hybrid clover (Trifolium hybridum).

NEUROLOGICAL DISEASES

Typical symptoms of poisoning with poisonous plants include blindness, lack of coordination, convulsions, depression, inability to chew food.

Hyperexcitability

The most incredible changes in horse behavior are caused by prolonged chewing of Astragalus. Such animals are hyperactive, move from place to place, shake their head, all this is accompanied by severe weakness.

Open mouth

If the horse's mouth is slightly open and he cannot take food and chew it, this is a symptom of poisoning with sun cornflower (Centaurea solstitialis) and bitterness (Acroptilon). Increased salivation is also observed.

Related article Non-communicable horse diseases

When poisoning with wormwood (Artemisia), trembling, convulsions are observed, the horse falls forward.

Blindness and tremors are caused by bracken (Pteridium), sensitive onoclea (Onoclea sensibilis), stevia (Eupatorium urticaefolium), field horsetail (Equisetum arvense).

Some plants contain a toxin called tremethol, which causes intense tremors throughout the body, inability to swallow, and signs of choking. It is found in plants such as the nettle-leaved steeple (Eupatorium urticaefolium) and the variegated aplopappus (Aplopappus heterophyllus).

Consumption of Sudanese (Sorghum sudanense) and Johnson grass (Sorghum halepensis) causes weakness in the back of the trunk, impaired coordination, and paralysis of the bladder. The horse backs away and sits down or falls back.

The increased selenium content of the feed can cause lameness in horses. Plants that contain selenium:

- Ionopsis, - Astragalus, - Aster cordifolius, - Amaranthus.

Black walnuts (Juglans nigra) cause severe hoof inflammation. It is vital that the horse's litter does not contain such nut shavings.

Green-gray hiccups (Berteroa incana) cause swelling of the limbs, fever and inflammation of the hoof.

ANEMIA

The main plant causing anemia is the red maple (Acer rubrum). The toxin, which is still unknown, can be found in dry (not green) foliage and bark. Even if a small amount of this plant enters the horse's body, after a couple of days the urine becomes red-brown, severe depression and symptoms of shock are observed.

Other plants that occasionally cause anemia are onions (Allium) and rotten sweet clover (Melilotus).

Related article How to protect a horse from disease?

HEART DISEASES

The following plants can cause heart problems and even death of a horse:

- foxglove (Digitalis), - euphorbia (Euphorbia) - some species, - oleander (Nerium), - lily of the valley (Convallaria), - hemp (Cannabis), - kendyr, or kutra (Apocynum).

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