Additional Common Names: Brake Fern, Umbewe, Brake, Pasture Bracken, Hog-Pasture Bracken, Eagle fern, Umhlashoshana, Adelaarsvaring
Scientific Name: Pteridium aquilinum
Toxicity: Toxic to Horses
Toxic Principles: Thiaminase
Clinical Signs: Poisoning commonly occurs in horses having inadequate forage, or when the plant is incorporated into hay. All parts of the plant are toxic in both green and dry forms. The toxic component causes a thiamine deficiency (an essential nutrient for central nervous system function and metabolism); clinical signs develop after one to two months of chronic ingestion, and can worsen over a two to three day period. Effects include weight loss, incoordination/ excessive staggering (known as "bracken staggers"), the developement of a wide stance with arched back, severe muscle tremors, inability to get up which could lead to serious injury. Death may occur within one to 2 days of onset if not treated.
If your pet ingested this plant, contact your local veterinarian or the ASPCA Animal Poison Control Center at 888-426-4435.*
* A $65 consultation fee may apply.Browse Toxic Plant Gallery List »