Farm and Garden Plants Poisonous to Goats and Other Livestock

Jun 8, 2010
Mike Bown

Rhododendron is Poisonous to Livestock - Ulaf Eliasson: Wikimedia Commons

A list of plants commonly found on farms and in many ornamental gardens that are poisonous to goats, sheep, cattle and horses.

Animals seem to know instinctively which plants they should not eat and poisoning occurs infrequently. However, some extremely poisonous plants are very palatable to livestock and actively sought, particularly if pasture supply or their normal feed source is scarce and animals are hungry.

Goats may be particularly susceptible to plant poisoning as they are naturally browsers rather than grazers and selectively feed on shrubs and trees, both leaves and bark. Animals run on smaller lifestyle farms may also be at risk as they are often farmed in close proximity to toxic plants grown in ornamental gardens around the homestead.

Young, immature animals may also be more susceptible to plant poisons because they are less able to detoxify plant toxins than older, heavier animals. Elderly or diseased animals may also be more susceptible to toxicosis due to reduced general resistance to physiological stress. Many plants that are toxic to livestock are also poisonous to children.

Poisonous Plants, Poisoning Symptoms and Signs

Acorns (Oak – Quercus species). Acorns contain a toxin which can suppress rumination and cause constipation.
Azalea (Azalea species). Very palatable to goats. Symptoms as for rhododendron poisoning with salivation, vomiting, rumen spasms colic, convulsions and death.
Box (Buxus sempervirens). Toxin causes stupefaction, vomiting, haemorrhagic diarrhoea, convulsions, cardiac and respiratory disturbance and death. Poisonings may occur after ingestion of box hedge clippings.
Hemlock (Conium maculatum). Toxic to all livestock. The toxin is a narcotic causing salivation, bloating, breathing difficulties, convulsions and paralysis.
Oleander (Nerium oleander). Extremely toxic in small amounts. Causes convulsions, vomiting, colic, bloody diarrhoea, cardiac arrhythmia and respiratory difficulties.
Japanese Pieris – Lily of the Valley Tree (Pieris japonica). Very palatable to goats. Symptoms similar to rhododendron poisoning with salivation, vomiting, rumen spasms colic, convulsions and death
Ragwort (Senecio jacobaea). Alkaloid toxins can cause liver damage and death. Horses are particularly vulnerable. Sheep and goats can partially detoxify the alkaloid in the rumen, though excessive intake can cause liver damage.
Rhododendron (Rhododendron species). Very palatable to goats but very toxic. Causes salivation, vomiting, rumen spasms, colic, convulsions and death. Possibly the most common plant poisoning in goats.
Yew (Taxus baccata). Very palatable to livestock and very toxic. Causes excitement, trembling, vomiting, staggering and death.
Macrocarpa (Cupressus macrocarpa). May cause abortion in sheep, cattle and sometimes goats, 7-14 days after ingestion.

Treatment for Plant Poisoning

Once symptoms are evident there is little that can be done practically to treat poisoned animals. Few specific antidotes to plant poisons are available and it is impractical to induce vomiting with emetics as it is difficult to empty a ruminant’s stomach.

If it is clear that an animal has ingested only a small amount of a poisonous plant it may be possible to slow down absorption of ingested toxins by administering activated charcoal or tannins (e.g. dosing with strong cold tea) and by keeping the animal quiet to reduce stress.

Where it is not clear what has caused the symptoms or the symptoms are severe advice from a veterinarian should be sought quickly. A veterinarian may need to sedate an animal showing nervous irritation until the poison has been eliminated from the body.

Prevent Plant Poisoning

Plant poisonings can be prevented by eliminating poisonous plants entirely from the farm or garden. If this is not possible or not desirable then secure fencing must be erected to prevent livestock from getting to and eating the toxic plants. It should be noted that dried windblown leaves of some plants (e.g. oleander, rhododendron and yew) are as toxic as the live plants.