Catsear
Hypochaeris radicata
Horse
Severe
Any suspected ingestion is an immediate veterinary emergency. Prolonged consumption, often during very dry summers when catsear is the only green plant remaining.
Equio informs, it does not diagnose. When in doubt, call your vet.
What to do now
- Antidote
- No specific antidote known. Symptomatic and supportive treatment.
- Time to signs
- Several weeks to several months of consumption
- Prognosis
- Guarded. Spontaneous recovery is possible if the horse is moved to a different pasture quickly, but it can take months or even years. Nerve damage may be permanent.
- Call a veterinarian immediately.
- Remove the horse from the contaminated pasture without delay.
- Ensure complete rest for the horse.
- Begin the treatment prescribed by the veterinarian.
Its ID card
- Height
- 20 cm – 1 m
- Flowering
- May to October
- Toxic parts
- Leaves, flowers, and stems.
- Toxin
- Toxins are poorly understood (suspected mycotoxins linked to an endophytic fungus within the plant).
- Habitat
- Dry pastures, sandy soils, overgrazed areas, old meadows.
- Soil indicator
- Acidic, very dry, sandy soils, degenerated old pastures.
- Regions
- Europe, Australia, New Zealand, Americas
- In hay
- Yes — stays toxic once dried
- Palatability
- Medium, but it is exceptionally drought-resistant, becoming the only source of fresh food in late summer.
When the risk rises
August to October (dry late summer, autumn).
Spotting it in the field
Dandelion (which is perfectly edible and very healthy for horses). — smell : slightly bitter and herbaceous smell, not very pronounced.
- Rosette of hairy leaves pressed to the ground.
- Hairy leaves, unlike the smooth dandelion leaves.
- Multiple yellow flowers resembling small dandelions.
- Branched flower stalks (unlike dandelion with a single flower per stalk).
Signs to watch for
Chronic (cumulative) toxicity
Dose : The exact dose is not established, but prolonged consumption of significant quantities is required.
- Stringhalt gait, horse lifts hind leg exaggeratedly up to the belly
- Extreme difficulty backing up
- Symptoms worsened by cold or stress
- Thigh muscle atrophy over time
- Laryngeal paralysis (roaring) in advanced cases
Who is affected
Other species : Poorly documented in other species, with a marked equine specificity.
In pregnant mares : no known direct abortifacient risk.
Getting rid of it
Method : Uproot the entire plant, including the root, before flowering. Avoid letting it spread by seeds. Burn uprooted plants to destroy toxins.
- Avoid overgrazing to maintain healthy grass cover.
- Supplement horses with hay during dry periods to reduce catsear intake.
- Identify and remove the plant before it flowers if possible.
Frequently asked questions
Can Equio identify Catsear from a photo?
It can help organize visual clues, but plant identification must remain cautious when horse health is at stake.
Is Catsear 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.