Research in the U.S.A suggests that thyroid disease in pet cats may be linked to dust shed from carpeting, upholstery and other household fabrics. Concerns about the possible health effects of polybrominated diphenyl ethers (PBDEs) arose in the late 1990s, and studies have reported that PDBEs cause liver and nerve toxicity in animals. Feline hyperthyroidism is one of the most common and deadly diseases in older cats, and indoor pets are thought to be most at-risk. cats ingest large amounts of PBDE-laden house dust that the researchers believe comes from consumer household products

Dr. Janice Dye of the U.S. Environmental Protection Agency's division in Research Park Triangle, N.C., led a team of scientists who found that PBDEs, may be involved in a disorder called feline hyperthyroidism. The chemical is used as a flame retardant in household fabrics and was found in elevated levels in blood samples from about a dozen cats nationwide.

The compound also has been found in some samples of fatty fish, such as salmon, and as a result is turning up in canned cat foods, Dye said.

"Manufacturers have been putting flame retardants in household products for about 30 years," Dye said in an interview, referring to upholstered furniture and carpeting. "Those are the perfect items that cats choose to sleep on.

"PBDEs seem to leach off in time and glom onto house dust. As a person, a little may get on your skin," she said, adding that daily bathing tends to get rid of it. "But if you're a cat you tend to lick it off, and because of their fastidious grooming habits they are eating a fair amount of it."

Cats who eat canned seafood-flavored products could be ingesting even more of the compound, which have PBDE levels 12 times as high as dry-food diets. Dye said pet cats might be receiving as much as 100 times greater dietary PBDE exposures than adult humans.

Feline hyperthyroidism causes exceptionally high heart and metabolic rates. The condition is similar to Graves disease in humans.

The chemicals act as endocrine-disrupting agents, Dye said. Endocrine disrupters are chemicals that interfere with the function of hormones. The thyroid produces the hormone thyroxin. Disrupters, linked to a variety of environmental toxins, have been drawing an increasing spotlight. Researchers at Stony Brook University have linked estrogen-based endocrine disrupters in Jamaica Bay to the transformation of male winter flounder into females.

"Thirty years ago we almost never saw this disease," Dye said. "Now it's the most common disease in older cats."

Not all Vets are convinced pointing out that it is such a relatively small study and that the disease itself is one of the most common conditons in cats.

Dye and her team report their results in the online edition of Environmental Science and Technology.