Researchers are reporting that a strange epidemic of thyroid disease in cats living in the U.S. may be related to dust from flame-retardant chemicals used in furniture, carpets, mattresses, electronics, and even pet food.
There is no evidence to suggest that the chemicals, polybrominated diphenyl ethers (PBDEs), pose a risk to humans, but the possibility cannot be ruled out. Researchers said that cats are highly exposed to chemicals, and the levels are higher in cats compared to people. This could be used as an indicator to gauge the indoor exposure to people.
Cats with hyperthyroidism may show the following symptoms: weight loss, increased appetite, hair loss and irritability. This disease is one of the most common and deadly illnesses in older felines. Due to their grooming habits, indoor cats are at a higher risk because they can ingest large amounts of dust containing PBDEs.
In this recent study, which is published in Environmental Science and Technology, the research team took blood samples from 23 cats. Eleven of them were diagnosed with hyperthyroidism. The cats with the illness measured levels of PBDEs three times higher than younger cats and cats without hyperthyroidism.
PBDEs can also be found in canned cat food, particularly in fish/seafood flavors, such as salmon and whitefish. An analysis showed that diets based on canned food could have PBDE levels 12 times higher than dry-food diets. Researchers stated that cats could be getting as much as 100 times greater PBDE exposure in their diets that humans.
Cats may have a higher risk of getting feline hyperthyroidism in the United States because people in the US have the highest reported PBDE levels among other countries. Also, by the late 1990s, North America accounted for almost 50% of the worldwide demand for PBDEs for commercial materials.
Feline hyperthyroidism is also being seen in Canada, Australia, Japan and many parts of Europe.
Concerns about the effects from PBDEs began in the late 1990s. Researchers have shown that these chemicals can cause liver and nerve toxicity in animals. There has also been a recent study that showed an association with house dust and the levels of PBDEs in women’s breast milk.
Various PBDEs, which have been used in polyurethane foam for cushions and pillows, have been phased out either by manufacturers or by bans from states and the U.S. government and other governments.
Amidst the bans, PBDEs will still take a long time to disappear from the environment because they are environmentally persistent compounds.
Source: U.S. News and World Report