Black Locust
Robinia pseudoacacia
Horse
Severe
Any suspected ingestion is an immediate veterinary emergency. 150 grams of bark is enough to poison a horse.
Equio informs, it does not diagnose. When in doubt, call your vet.
What to do now
- Antidote
- No specific antidote. Intensive symptomatic treatment: IV fluids, laxatives, anti-colics, cardiac monitoring.
- Time to signs
- 15 minutes to a few hours
- Prognosis
- Generally good if treated promptly. The outcome is rarely fatal if the ingested quantity remains low, but colic can be severe.
- Call the veterinarian.
- Administer activated charcoal if advised.
- Treat colic symptomatically.
- Ensure adequate hydration.
Its ID card
- Height
- 10 m – 30 m
- Flowering
- May to June
- Toxic parts
- Bark, seeds, roots, young shoots (flowers are edible in fritters for humans, but should be avoided for horses).
- Toxin
- Phytotoxins (Robinine and phasin)
- Habitat
- Open woodlands, embankments, spoil heaps, hedges, and especially used for park fencing posts.
- Soil indicator
- Poor, sandy, dry soils. Pioneer species.
- Regions
- Europe, North America
- In hay
- Yes — stays toxic once dried
- Palatability
- The bark is sweet and highly appreciated by horses, who like to gnaw on it (especially out of boredom in winter).
When the risk rises
Winter (bark gnawed due to lack of grass) and Spring.
Spotting it in the field
Acacia (true), Sophora, Gleditsia. — smell : the flowers have a sweet and strong scent. leaves and bark do not have a notable distinctive smell.
- Thorny tree.
- Leaves composed of numerous small oval leaflets.
- Clusters of very fragrant (nectar-bearing) white flowers in spring.
- Flat brown pods in autumn.
Signs to watch for
Acute toxicity.
Dose : Approximately 150 g of bark or leaves for a 500 kg horse.
- Colic and diarrhea
- Dilation of the pupils (mydriasis)
- Weakness in the hindquarters
- Sweating and cardiac arrhythmia
- Paralysis and coma (in severe cases)
Who is affected
Other species : Cattle and sheep are also susceptible.
In pregnant mares : no direct abortifacient risk documented, except for shock related to colic.
Getting rid of it
Method : Pull up young plants before fruiting. Posts must be debarked and dried. Burn toxic parts if possible.
- Eliminate horse access to un-debarked Black Locust posts.
- Closely monitor horses during winter and spring for any gnawing behavior.
- Identify and remove Black Locust plants from pastures.
Frequently asked questions
Can Equio identify Black Locust from a photo?
It can help organize visual clues, but plant identification must remain cautious when horse health is at stake.
Is Black Locust dangerous in hay?
This entry flags hay vigilance. Isolate suspicious forage and ask for professional advice if exposure is possible.
This page is informational. If ingestion is likely, if signs appear, or if the horse is fragile, contact a veterinarian immediately.