Broadleaf Dock / Common Sorrel
Rumex obtusifolius / Rumex acetosa
Horse
Low
Remove access and monitor the horse; call at the first sign. A very large quantity ingested over several weeks (often when it's the only forage available in the pasture).
Equio informs, it does not diagnose. When in doubt, call your vet.
What to do now
- Antidote
- No specific antidote. Symptomatic management and renal/bone support if necessary.
- Time to signs
- Several weeks to several months for chronic effects.
- Prognosis
- Very good. Severe cases in adult horses are rare, as it would require the horse to have no other food source.
- Remove from the infested pasture.
- Supplement with calcium if tremors are observed, on veterinary advice.
Its ID card
- Height
- 30 cm – 1.5 m
- Flowering
- June to September.
- Toxic parts
- Leaves (especially fresh ones).
- Toxin
- Oxalic acid and oxalates
- Habitat
- Overgrazed pastures, compacted soils, trampled areas (around feed/water troughs), nitrogen-rich soils.
- Soil indicator
- Compacted (suffocated) soils, overgrazing, excess nitrogen and potassium.
- Regions
- Entire Europe, Cosmopolitan
- In hay
- Yes — stays toxic once dried
- Palatability
- Low (acidic/sour taste). Consumed due to lack of grass or, curiously, by some horses that develop a taste for the sorrel's acidity.
When the risk rises
April to October.
Spotting it in the field
Burdock (much larger, hairy leaves), Arum lily (smooth, arrow-shaped leaves but highly toxic). — smell : slightly acrid when crushed, especially for rumex acetosa.
- Large, broad leaves (Rumex obtusifolius) or arrow-shaped leaves (Rumex acetosa).
- Stiff, upright stem turning reddish-brown in late summer.
- Seeds in dense, reddish-brown clusters that persist long into winter.
Signs to watch for
Chronic (cumulative) toxicity due to oxalate accumulation.
Dose : Chronic and massive ingestion over several weeks (several kilograms of fresh leaves per day).
- Mild to moderate diarrhea
- Muscle tremors (related to low blood calcium)
- Cloudy or bloody urine (kidney stones)
- Weight loss if chronic consumption
- General weakness
Who is affected
Other species : Toxic to sheep (very susceptible to kidney stones) and cattle.
In pregnant mares : calcium deficiency can be detrimental to fetal development.
Getting rid of it
Method : Manual uprooting of the taproot before flowering. Repeated mowing. Avoid overgrazing.
- Maintain good pasture management to prevent overgrazing.
- Identify and remove the plant before it goes to seed.
- Ensure a balanced and diverse diet for horses.
Frequently asked questions
Can Equio identify Broadleaf Dock / Common Sorrel from a photo?
It can help organize visual clues, but plant identification must remain cautious when horse health is at stake.
Is Broadleaf Dock / Common Sorrel 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.