Per- and polyfluoroalkyl substances in Northern California cats: Temporal comparison and a possible link to cat hyperthyroidism

[helvella]

Just watching our cat on the sofa and hoping she doesn't know what I am posting.

Environ Toxicol Chem. 2018 Oct;37(10):2523-2529. doi: 10.1002/etc.4239. Epub 2018 Sep 19.

Per- and polyfluoroalkyl substances in Northern California cats: Temporal comparison and a possible link to cat hyperthyroidism.

Wang M1, Guo W1, Gardner S2, Petreas M1, Park JS1.

Author information

1 Department of Toxic Substances Control, California Environmental Protection Agency, Berkeley, California, USA.

2 Albany Animal Hospital, Albany, California, USA.

Abstract

The indoor environment and dietary intake are considered to be major human exposure pathways to per- and polyfluoroalkyl substances (PFASs). Cats have similar exposures to humans by sharing their residential environments, although they have different diet, body sizes, and indoor activities. In the present study, we report PFAS levels in the serum of 2 groups of Northern California cats (>10 yr old) collected during 2 time periods: 2008 to 2010 (n = 21) and 2012 to 2013 (n = 22). Levels of ∑PFAS (geometric mean) were lower in the second period (geometric mean = 8.10 ng/mL) than the first time period (geometric mean = 15.8 ng/mL), although PFAS profiles remained similar. We also analyzed PFAS levels in human serum collected in the same time period (2008-2010) and geographic area, and compared the profiles and ∑PFAS levels (15.8 vs 14.3 ng/mL for cat and human, respectively). Long chain perfluorinated carboxylic acids, especially perfluorononanoic acid and perfluoroundecanoic acid, were significantly higher in cat serum than in humans. Furthermore, serum from hyperthyroid cats in the second time period showed higher ∑PFAS level (9.50 ng/mL) compared to nonhyperthyroid cats (7.24 ng/mL), and it is the perfluorooctanoic acid levels that were statistically significantly higher in hyperthyroid cats' serum (p < 0.05). This result may indicate a possible link between PFAS levels and cat hyperthyroid, warranting a larger study for further investigation. Environ Toxicol Chem 2018;37:2523-2529.

© 2018 SETAC.

KEYWORDS:

Cat hyperthyroidism; Cat serum; Human serum; Per- and polyfluoroalkyl substances; Perfluorooctanoic acid

PMID: 30229994

DOI: 10.1002/etc.4239

ncbi.nlm.nih.gov/pubmed/302...

A little about perfluorononanoic acid:

en.wikipedia.org/wiki/Perfl...

A little about perfluoroundecanoic acid:

pubchem.ncbi.nlm.nih.gov/co...

[jimh111]

PBDEs are associated with hyperthyroidism in cats: ncbi.nlm.nih.gov/pubmed/223... ncbi.nlm.nih.gov/pmc/articl... . It may be that PFASs correlate with PBDEs and so do not cause hyperthyroidism in cats. I would need to study the full paper to get an idea. I don't know anything about PFASs. Although PBDEs cause hyperthyroidism in cats they seem to cause hypothroidism in humans. Different animals have different exposure routes and elimination half lives are less in smaller animals. These substances can have many different forms ('congeners') so the congener profile varies between species. This along with subtle effects on thyroid hormone receptors between species can lead to different effects.

It's a long time since I read the PBDE cats study so can't comment on the details.

[LAHs]

Oh what a little beauty!!!!! Is that your cat Helvella?

Since 2008 - present day I have had 8 Northern Californian cats 4 of whom were known to have had hyperthyroidism that's a 50% known occurrence. I have been administering metamazole (?sp) everyday to either one or two of them since 2008. Thank goodness they have it in ear rubbing paste now, pills were terrible, especially twice a day for one of them. Fortunately they all got it when they were pretty old, one (Twinkle) was 22 years old so maybe her death should be attributed to old age. I just have one with hyperthyroidism now (Sandy) so one ear rub per day is quite manageable. The 4 cats who were ill were diagnosed by the vet, so maybe their statistics are in the study. And again, what a little beauty - I LOVE cats.

[helvella Administrator Thyroid UK in reply to LAHs]

No - not ours. Of course, ours is at least as beautiful but has more conventional colour eyes. (And I certainly haven't taken such a good photo. )

[jgelliss]

WOW !!! What A Gorgeous Cat . Those color eyes are amazing .