Cats are falling ill with thyroid disease caused by toxic flame retardants found in household dust and some pet food, says the EPA. Chemicals known as PBDEs—polybrominated diphenyl ethers—found in consumer products and furniture are mimicking hormones which send a cat's thyroid into overdrive. Since humans are the only other mammal with a high rate of hyperthyroidism, the common chemicals could be affecting them, too.
"It is clear that house cats may be able to serve as sentinels for indoor exposure to PBDEs for humans who share their houses," said a leading expert on hormone-altering chemicals. Symptoms of the cat-killing ailment include weight loss, rapid heartbeat and irritability; its frequency has spiked since the 1980s, when the retardants were introduced, the Los Angeles Times reports,