Silicone Pet Tags Associate Tris(1,3-dichloro-2-isopropyl) Phosphate Exposures with Feline Hyperthyroidism

Abstract

Feline hyperthyroidism is the most commonly diagnosed endocrine-related disease among senior and geriatric housecats, but the causes remain unknown. Exposure to endocrine-disrupting compounds with thyroid targets, such as flame retardants (FRs), may contribute to disease development. Silicone passive sampling devices, or pet tags, quantitatively assessed the bioavailable FR exposures of 78 cats (≥7 y) in New York and Oregon using gas chromatography–mass spectrometry. Pet tags were analyzed for 36 polybrominated diphenyl ethers, six organophosphate esters (OPEs), and two alternative brominated FRs. In nonhyperthyroid cats, serum free thyroxine (fT4), total T4 (TT4), total triiodothyronine, and thyroid-stimulating hormone concentrations were compared with FR concentrations. Tris­(1,3-dichloro-2-isopropyl) phosphate (TDCIPP) concentrations were higher in hyperthyroid pet tags in comparison to nonhyperthyroid pet tags (adjusted odds ratio, p < 0.07; Mantel–Cox, p < 0.02). Higher TDCIPP concentrations were associated with air freshener use in comparison to no use (p < 0.01), residences built since 2005 compared to those pre-1989 (p < 0.002), and cats preferring to spend time on upholstered furniture in comparison to no preference (p < 0.05). Higher TDCIPP concentrations were associated with higher fT4 and TT4 concentrations (p < 0.05). This study provides proof-of-concept data for the use of silicone pet tags with companion animals and further indicates that bioavailable TDCIPP exposures are associated with feline hyperthyroidism.

“State of the Mewnion”: Practices of Feral Cat Care and Advocacy Organizations in the United States

“…When asked if they were seeing health issues in feral cats suspected of being caused by exposures to toxins or environmental contaminants, 13.8% respondents reported yes, 59.0% of reported no, and 27.2% reported that it was unknown (n = 544). In categorizing write-in explanations, the common trends for those reporting a concern were chemical or toxic exposures (51), infectious diseases (10), climate and weather related issues (5), reproductive issues and birth defects (4), suspected cancers and carcinogens (4), and firearms (3). Some respondents suspected observing health issues in feral cats caused by environmental exposures, with the intentional poisoning of cats as the most commonly-mentioned problem.…”

“…A vast majority had not (90.2%), and some were unsure (5.6%) or reported yes (4.2%) (n = 449). By grouping the write-in answers for those who had sought help, the 2 most common type of entities contacted were veterinarians and academics (6) and cat welfare organizations (5), and the only motivating needs mentioned by more than 1 group were planning their spay/neuter programs (2) and quantifying cats (2). Inversely, we also asked if a group had ever been contacted by an academic or researcher who wanted to work with them or collect data about their organization.…”

“…In asking those who reported yes to explain who had contacted them and why, the most common write-in explanations were cat welfare organizations (13), students (9), and academics (7). The write-in reasons for the contact included someone seeking statistics and data (7), interest in animal welfare and behavior (7), bird and wildlife issues (5), disease and medical issues (5), and seeking biological samples (4).…”

“…For example, when a large episode of mercury poisoning occurred in communities living near Minamata Bay in Japan in the 1950s, local cats were the first ones to show symptoms because they had greater exposure to contaminated fish and accumulated a toxic level of mercury faster than humans ( 3 ). Similarly, cats are studied as sentinels for lead ( 4 ), flame retardants ( 5 ), chlorinated pollutants ( 6 ), and infections such as avian influenza ( 7 ). A feral cat presenting as having been poisoned may indicate a risk to people in the area who could also make contact with the substance.…”

Firefighter exposures to potential endocrine disrupting chemicals measured by military-style silicone dog tags

“…To prevent adverse health outcomes, it is useful to investigate what factors contribute to higher pEDC exposures. Previous literature has examined both environment- and participant-based factors associated with higher chemical exposures ( Dixon et al, 2019 ; Fent et al, 2017 ; Fent et al, 2018 ; Gibson et al, 2019 ; Poutasse et al, 2019 ; Poutasse et al, 2020 ; Reddam et al, 2020 ). For instance, urinary flame retardant metabolite concentrations decrease with increased hand washing and house cleaning ( Gibson et al, 2019 ); and concentrations of the flame retardant tris(1,3-dichloro-2-isopropyl) phosphate increase with longer driving commutes ( Reddam et al, 2020 ) and more time spent on upholstered furniture ( Poutasse et al, 2019 ).…”