Field Pennycress Toxic?

Updated 2026-03-06| 2 min read| 2,809 found this helpful

Field Pennycress is confirmed toxic to horses, while toxicity risks for cats and dogs remain unstudied and unknown.

Its primary toxic principle is isothiocyanates, a class of irritant compounds common to many Brassicaceae species.

Confirmed exposure symptoms in horses include gastrointestinal distress (colic, diarrhea) and contact dermatitis.

FAQ

Is Field Pennycress toxic to Humans?

No confirmed human toxicity data available; incidental exposure may cause mild skin or mucous membrane irritation (Low)

Is Field Pennycress toxic to Cats?

Toxicity status unknown, no documented clinical exposure symptoms reported to date (Unknown)

Is Field Pennycress toxic to Dogs?

Toxicity status unknown, no documented clinical exposure symptoms reported to date (Unknown)

Is Field Pennycress toxic to Horses?

Colic, diarrhea, contact dermatitis (Moderate)

Not sure which plant? Snap a photo to ID in 1 secondGet App

Toxicity Details

Humans

Low

No confirmed human toxicity data available; incidental exposure may cause mild skin or mucous membrane irritation

Cats

Unknown

Toxicity status unknown, no documented clinical exposure symptoms reported to date

Dogs

Unknown

Toxicity status unknown, no documented clinical exposure symptoms reported to date

Horses

Moderate

Colic, diarrhea, contact dermatitis

Toxicity Snapshot

Toxic PartsAll above-ground plant parts (leaves, stems, seeds) are considered toxic, with seeds containing the highest concentration of isothiocyanates

Exposure RouteIngestion (primary exposure route for grazing horses), direct skin contact with fresh plant material

Toxic CompoundsIsothiocyanates

First Aid & Prevention

First 30 Minutes

• Remove all remaining Field Pennycress from the affected animal's access, and rinse plant material from the mouth for recent ingestions
• Rinse skin contact sites with cool clean water for 10-15 minutes to reduce dermatitis risk
• Collect a sample of the suspected plant for accurate identification by veterinary staff

Contact Vet Immediately

• A horse is observed ingesting any quantity of Field Pennycress, even if no symptoms are present
• Any animal exhibits colic, diarrhea, or unexplained dermatitis after potential exposure to this plant
• You are unsure if your pet or livestock has ingested this plant and observe unusual behavioral changes

Prevention

• Inspect horse grazing pastures regularly and manually remove all identified Field Pennycress growth
• Avoid feeding hay or forage contaminated with Field Pennycress to horses
• Keep toxic Brassicaceae ornamental and weed species out of reach of companion pets and livestock

Treatment & Prognosis

• Veterinarians may administer activated charcoal for recent large ingestions to reduce toxin absorption
• Supportive care including fluid therapy and anti-diarrheal medication may be provided to address gastrointestinal symptoms
• Topical anti-inflammatory treatments may be prescribed for contact dermatitis cases

Emergency? Open PlantFun for real-time AI guidanceGet App

Professional Toxicology

Scientific NameThlaspi arvense

AliasesStinkweed、Frenchweed、Field Pennygrass

Toxicity Grade

HumansLow

CatsUnknown

DogsUnknown

HorsesModerate

Target Organs

Gastrointestinal tractSkin

Mechanism of Action

• Isothiocyanates act as mucosal irritants when ingested, causing inflammation of the gastrointestinal tract lining

• Direct contact with plant compounds triggers localized inflammatory responses in skin tissue leading to dermatitis

Other Species Risk (CliniTox)

Information from CliniTox veterinary text.

Cattle: Limited data available; large ingestion is expected to cause mild gastrointestinal irritation similar to symptoms seen in horses

Sheep: Toxicity not well documented; sheep show higher tolerance to isothiocyanate exposure than horses, with low expected risk of severe symptoms

Confusion Risk

The following plants look similar and may be confused:

Shepherd's Purse Capsella bursa-pastoris

Both are small widespread Brassicaceae weeds with white flowers; Field Pennycress has wide flat seed pods and a pungent garlic-like odor when crushed, while Shepherd's Purse has narrow purse-shaped seed pods

Wild Mustard Sinapis arvensis

Both are common agricultural weeds in the Brassicaceae family found in the same pasture habitats; Wild Mustard produces bright yellow flowers, while Field Pennycress has small white flowers

Use PlantFun to scan and avoid misidentificationGet App

Related Toxic Plants

Black Mustard

Brassica nigra

Moderate toxicity, contains isothiocyanates that cause severe gastrointestinal irritation in livestock

Wild Radish

Raphanus raphanistrum

Moderate toxicity, causes gastrointestinal distress and photosensitivity in grazing animals

Rapeseed

Brassica napus

Low to moderate toxicity, may cause hemolytic anemia in horses if ingested in large quantities

Download PlantFun App

Identify, grow and care for plants effectively!

Instant Plant ID

Take a photo to quickly identify plants.

Smart Care Reminders

Generate watering and care schedules.

Toxicity & Disease Diagnosis

Identify toxic plants and pests with treatment advice.

Data Sources

1. ASPCA Animal Poison Control

This information is for reference only and does not constitute medical advice. If ingestion or poisoning is suspected, seek medical or veterinary attention immediately.