Pteridium aquilinum is toxic to horses. The reported severity is severe. Also known as Common Bracken, Eagle Fern and Hairy Brackenfern.
This plant is known to be potentially deadly!
If your animal ate this plant, call your veterinarian now, or one of these services.
What do I do right now?
Ireland has no animal poison service for owners. Call your veterinarian. An Irish veterinarian can consult the Veterinary Poisons Information Service in the United Kingdom.
Giftinformationscentralen stopped answering questions about animals on 1 July 2018. Call your veterinarian or an animal hospital.
Weakness Weight Loss Incoordination Tremors Death
The color of each symptom follows the severity scale above.
Pteridium aquilinum, commonly called bracken, brake, pasture brake, common bracken, and also known as eagle fern, is a species of fern occurring in temperate and subtropical regions in both hemispheres. Originally native to Eurasia and North America, the extreme lightness of its spores has led to it achieving a cosmopolitan distribution.
The plant contains the carcinogenic compound ptaquiloside. Ptaquiloside is known to cause haemorrhagic diseases in ruminants, tumours and haematological problems in non-ruminants, and is correlated with oesophageal and gastric cancer in humans. Chronic bracken consumption is also associated with upper digestive tract (UDT) squamous cell carcinomas in cattle (ruminants)—with the most aggressive and serious tumors located in the caudal (lower) UDT. High stomach cancer rates are found in Japan and North Wales, where the young stems are used as a vegetable, but it is unknown whether bracken plays any part or if the cancer can be attributed to another cause. Consumption of ptaquiloside-contaminated milk is thought to contribute to human gastric cancer in the Andean states of Venezuela. The spores have also been implicated as carcinogens. Consumption of contaminated water and meat may be dangerous as well. However, ptaquiloside is water-soluble, and is reduced by soaking bracken in cool water. Korean and Japanese cooks have traditionally soaked the shoots in water and ash to detoxify the plant before eating. Ptaquiloside also degenerates at room temperature, which explains why the rat studies were done with the toxin stored at −20 °C (−4 °F). At boiling temperature, the carcinogen denatures almost completely. Salt and baking soda also help with volatilizing the chemical. It has been suggested that selenium supplementation can prevent as well as reverse the immunotoxic effects induced by ptaquiloside from Pteridium aquilinum.
Also recorded as Bracken, Bracken Fern, Brake, Northern Bracken Fern and Western Brackenfern.
More plants with severe severity:
Countries with the most wild observations, from GBIF data.