May 15, 2003

Canaries in the Kitchen: An agonizing death

In cases of “Teflon toxicosis,” as the bird poisonings are called, the lungs of exposed birds hemorrhage and fill with fluid, leading to suffocation. In a laboratory study in which birds were killed by non-stick fumes, Dr. Roger Wells, a veterinarian at Michigan State University, characterized the response in many of the exposed birds as “acute respiratory distress and rapid death” [1]. Wells' description of the progression of death in a group of birds exposed to PTFE fumes is consistent with most other documented cases of Teflon toxicosis, in which birds suffer for minutes or even hours before death:

“Clinical signs of toxicosis were varied and began with eyelid blinking at 8 to 10 minutes of exposure and progressed to open-beak panting, biting at the wire cage, incoordination, wing stretching and flapping, and chirping, and usually ended in a terminal convulsion, with the birds recumbent on their sides or backs.”

The birds in this exposure group died within 17 to 27 minutes of exposure. In the same study birds in a lower dose group died up to 11 hours after exposure. The observations of pet bird owners who have lost birds to Teflon toxicosis are consistent with Wells' descriptions. Bird owners have described their birds gasping for breath, or laboring for breath with head bobbing back and forth before death. | View Bird death diaries

Scientists who have studied the lungs of birds killed by Teflon fumes find common signs of gross lung damage, including severe lesions in the most sensitive birds. Hallmark signs of PTFE poisoning in birds are lung congestion, fluid accumulation of the lung (edema), bleeding in the lung (hemorrhage), heart tissue death (necrosis of the atrial epithelium) and crystalline particulate deposition in certain lung cells (parenchyma). Autopsies also show brain hemorrhage, liver congestion, degeneration and necrosis; and heart muscle (myocardial) degeneration and necrosis.

Dr. Larry Thompson, a resident in veterinary toxicology at the University of Illinois College of Veterinary Medicine at Champaign-Urbana, says birds affected by Teflon toxicosis "show acute respiratory distress, dyspnea or difficulty breathing; they go into little rocking movements, ataxia; they look asleep or somnolent; then they go into agonal convulsions" [2]. In another account, the progression of death is described: “...the birds’ lungs are scorched, causing blood vessels to rupture, and, within minutes, the poor animals literally suffocate in their own blood.” [3].


[1] Wells RE, Slocombe RF, Trapp AL. 1982. Acute toxicosis of budgerigars (Melopsittacus undulatus) caused by pyrolysis products from heated polytetrafluoroethylene: clinical study. Am J Vet Res 43:1238-42.

[2] Daniels, Mary. 1986. “Stove fumes killing cages birds; overheating coated pans can bring quick death,” Chicago Tribune. March 9, 1986.

[3] Dale, Steve. 1995. “Fatal fumes; while people may not be in danger, the kitchen is no place for pet birds.” Chicago Tribune. March 26, 1995.