Dogs and cats can be exposed to a group of potentially toxic chemicals in their homes, with finding them in the feces of pets a sign of health problems for humans living with them, according to a new study.
Called aromatic amines, the chemical substances -; found in tobacco smoke and in dyes used in cosmetics, textiles and plastics -; are known to cause cancer. Notably, the study found that tobacco smoke was not a major source of pet exposure, suggesting that the latter products were likely the main culprits.
Led by researchers at NYU Grossman School of Medicine, the study identified eight types of aromatic amines in stool samples taken from dozens of dogs and cats. It also found traces of the chemicals in more than 38% of urine samples taken from a separate group of pets.
Our results suggest that pets come into contact with aromatic amines leaching from products in their home environment. As these substances have been linked to bladder, colorectal cancer and other forms of cancer, our findings may help explain why so many dogs and cats develop such diseases.”
Sridhar Chinthakindi, PhD, Study Lead Author, Postdoctoral Fellow at NYU Langone Health
He adds that the results suggest that aside from these direct exposures, pets are likely exposed indirectly. For example, previous research has shown that a common flea drug called amitraz can be broken down into an aromatic amine called 2,6-dimethylaniline by microbes living in the digestive system of animals. It was the most commonly detected aromatic amine in the new study, accounting for nearly 70% of those found in dogs and nearly 80% of those found in cats.
Previous surveys by the study authors have measured other hormone-disrupting chemicals, including phthalates, melamine and bisphenols in the urine of pets. However, the new study, published online March 30 in the journal International Environmentis the first designed to explore pet exposure to aromatic amines in the household, according to Chinthakindi.
For the investigation, the research team collected urine samples from 42 dogs and 21 cats living in private households, veterinary hospitals and animal shelters in Albany, NY. They also collected fecal samples from 77 other pets living in the same area. They recorded all ages, breeds and sexes of animals. Next, the research team analyzed the samples for 30 different types of aromatic amines and nicotine.
Among the findings was that cats had at least triple the concentrations of aromatic amines in their urine as dogs, although the study authors say greater exposure and differences in metabolism between both species likely play a role in the concentrations of the chemicals found. Notably, cats do not break down many compounds as efficiently as dogs.
The survey also showed little difference in exposure to aromatic amines between animals that lived at home versus those that lived in a shelter or those that stayed in a veterinary hospital. According to Chinthakindi, this highlights how often these substances appear and how difficult it is to avoid them.
“Because companion animals are smaller and more susceptible to toxins, they serve as excellent ‘canaries in the coal mine’ for assessing chemical risks to human health,” says the study’s lead author. , Kurunthachalam Kannan, PhD, professor in the Department of Pediatrics at NYU Langone. . “If they are exposed to toxins in our homes, we better take a closer look at our own exposure.”
Kannan, also a professor at the Center for Investigation of Environmental Hazards at NYU Langone, warns that it remains unclear what levels of aromatic amines can be safely tolerated by pets, and so far no limits have been found. has been set by regulatory bodies for their protection.
He adds that the study authors next plan to explore the link between exposure to aromatic amines and bladder, thyroid and testicular cancer in companion animals.
Chinthakindi, S & Kannan. K., (2022) Urinary and fecal excretion of aromatic amines in United States pet dogs and cats. international environment. doi.org/10.1016/j.envint.2022.107208.