Plants and feed toxic to livestock

Learn about common toxic plants and how to prevent, diagnose and manage poisoning in cattle and other livestock.

Ingesting toxic plants and unsuitable feed supplements such as bread (or grains in small ruminants) can cause serious health problems for livestock.

Often, the greatest risk is when you have moved animals to a new paddock, or during drought when pastures are poor and food is scarce.

The best prevention is to eliminate weeds from your property. Treatment is not always successful (or possible) and can be very expensive.

Types of toxic plants

Bracken fern

Lantana

lantana

There are more than 30 colour forms of Lantana.

Lantana poisoning is generally associated with ingestion of the orange/red flowering plants rather than the lighter pink flowering variety, however all are toxic.

Ingestion of lantana causes liver damage and successful treatment depends on how much has been consumed and over what timeframe.

Death can occur anywhere from 2 days to 3 weeks after ingestion.

Plant type	Lantana
Scientific name	Lantana camara
Appearance	Toxic forms include: most red and orange flowered forms most pink flowered forms (north of Rockhampton) Helidon white form (in South East Queensland).
Distribution and habitat	Coastal and subcoastal Queensland and NSW, on a range of soil types and forest types
Toxic to	Ruminants
Poisoning circumstances	When cattle are introduced to unfamiliar surroundings containing the plant or during droughts or floods when regular feed is sparse
Clinical signs	loss of appetite and frequent urination, followed by constipation and dehydration dermatitis of unpigmented skin (such as muzzle, tongue) jaundice (look at the gums and other mucous membranes) seeking shade in severely affected cattle, diarrhoea with smelly black faeces.
How to treat	drench cattle with activated charcoal to reduce toxin absorption, and apply a second dose of charcoal and rehydration therapy before recovery starts keep affected animals in the shade.
How to prevent and control	Clear and/or burn pasture. Over-sow with competitive pasture species. Spray regrowth with herbicide. Controlled grazing.

Poison peach

poison peach

This inconspicuous plant causes acute liver damage (periacinar necrosis).

Most animals die within 2 or 3 days of ingesting it.

Native plant nurseries often stock it.

Plant type	Poison peach
Scientific name	Trema tomentosa
Apppearance	evergreen shrub or small tree up to 7.5m tall light green, ovate leaves 2cm to 8cm long, 1cm to 3cm wide, spreading out horizontally in one plane and often drooping inconspicuous flowers (3mm to 4mm); black, fleshy berries when fruiting.
Toxic to	Ruminants, horses, deer and camels
Toxin	Trematoxin, a glycoside of unknown composition
Distribution and habitat	Eastern and Northern Australia, frequently distributed in coastal or near coastal regions widespread in rainforest margins, in moist sclerophyll forest and softwood scrub regrows vigorously after land clearing.
Poisoning circumstances	heavy mortalities frequently occur in cattle newly introduced to country carrying poison peach no regular seasonal pattern of toxicity of any consistent association with soil type or time of year
Clinical signs	Most animals show symptoms on day 2 or 3 after exposure and die within 3 days: early symptoms: a tendency to lie down, loss of appetite, slightly increased salivation later symptoms: depression, ruminal stasis, abdominal pain, anorexia, recumbency, coma and death you may also notice: jaundice, muscle tremors, shallow jerky respiration, hyperexcitability, increased aggression, mania, blindness, lack of response to external stimuli and convulsions.
Pathology	haemorrhages under the membranes of the heart (myocardial, subendocardial and subepicardial) and under the skin serous membranes enclosing the abdominal organs inflammation in the abomasum and the proximal portion of the small intestine congestion of the lungs and mottling of the liver due to congestion.
How to treat	No known effective treatments; although cattle sometimes eat it without ill effect, always regard it as potentially poisonous
How to prevent and control	Deny access

Wild tobacco

wild tobacco

There are many species of poisonous wild tobacco, including devil’s apple and boxthorn.

These plants cause intense abdominal discomfort, severe diarrhoea and sometimes death.

Plant type	Wild tobacco
Scientific name	Solanum mauritianum
Appearance	annual herbs or large, soft-wooded shrubs up to 4m tall grey-green trunk with tapered 30cm long x 10cm wide leaves dense felt-like hairs on stems, leaves or flower’s calyx star-shaped white or blue/purple flowers with yellow stamens, in clusters at the end of branches small fruit that turn from green to yellow when ripe, with 150 to 200 flattened seeds.
Toxic to	Livestock
Distribution and habitat	pastures in coastal Queensland and NSW roadsides, disturbed areas, waterways and waste areas tolerates various soils and moderate shade.
Poisoning circumstances	Birds and flying foxes spread seeds
Clinical signs	diarrhoea, sometimes bloodstained nausea in some cases, dilated pupils emaciation with a rough coat, loss of appetite, constipation and abdominal dropsy Intoxicated animals sometimes die within a short time while others can recover
How to prevent and control	don’t allow hungry stock access to plants ringbark tall plants as close to ground as possible pull out seedlings in wet season when soil is soft assume any species is potentially poisonous unless determined otherwise applies at least to the leaves and immature fruits ripe fruits of many species are safe.