Over the years, researchers have theorized about lots of possible causes of hyperthyroidism in cats.
Remember the cat food can scare? Scientists thought the BPA in the lining of cans could make cats hyperthyroid.
And then there was the idea that the PCBs and PBDEs in flame retardant upholstery fabric were the culprits.
But now there's a new suspect: fish-flavored cat food.
PCBs and PBDEs can occur naturally in fish, leading a team of Japanese researchers to wonder whether cats are exposed to these harmful compounds from their food.
Led by Mizukawa Hazuki, assistant professor at the Center for Marine Environmental Studies, Ehime University, the team measured the residue levels of the compounds and their byproducts in commercial cat foods. Then they tested blood samples from cats and simulated how a cat’s body would process PCB- and PBDE-related compounds.
The blood samples contained high levels of both compounds, leading the researchers to believe they came from the cats' fishy food, not their environment.
But wait. Don't toss out all those cans of fish-flavored cat food just yet. The researchers say more work is needed to determine whether these compounds actually contribute to feline hyperthyroidism.
If you want to look it up, the study was published Dec. 2 in the American Chemistry Society’s Environmental Science & Technology journal.
and it doesn't contain fish.