Aromatic Amines in Pet Urine and Feces Could Be a Sign of Human Health Risks

According to a new study, dogs and cats may be exposed to a potentially dangerous collection of chemicals in their homes, with their finding in the pets’ stool indicating health risks for humans living with them.

The compounds contained in tobacco smoke and colors used in cosmetics, textiles, and plastics, known as aromatic amines, are known to cause cancer. Notably, the study found that cigarette smoke was not a significant cause of pet exposure, implying that it was the latter items that were to blame.

The study, led by NYU Grossman School of Medicine experts, discovered eight different forms of aromatic amines in stool samples from dozens of dogs and cats. It also discovered evidence of the compounds in over 38% of urine samples from a different set of pets.

“Our findings suggest that pets are coming into contact with aromatic amines that leach from products in their household environment,” says study lead author Sridhar Chinthakindi, Ph.D., a postdoctoral fellow at NYU Langone Health.

“As these substances have been tied to bladder, colorectal, and other forms of cancer, our results may help explain why so many dogs and cats develop such diseases.”

He goes on to say that, aside from such direct exposures, pets are most likely infected indirectly. Microbes dwelling in animals’ digestive tracts, for example, can break down a common flea control medicine called amitraz into an aromatic amine called 2,6-dimethylaniline, according to previous study.

Since pets are smaller and more sensitive to toxins, they serve as excellent ‘canaries in the coal mine’ for assessing chemical risks to human health. If they are getting exposed to toxins in our homes, then we had better take a closer look at our own exposure.

Kurunthachalam Kannan

The most prevalent aromatic amine revealed in the latest study was this one, accounting for about 70% of those found in dogs and nearly 80% of those found in cats. Other hormone-disrupting chemicals, including as phthalates, melamine, and bisphenols, have been measured in pet urine by the study authors in the past.

According to Chinthakindi, the new study, which was published online March 30 in the journal Environment International, is the first to look into pet exposure to aromatic amines in the home.

The researchers gathered urine samples from 42 dogs and 21 cats residing in private homes, veterinary facilities, and animal shelters in Albany, New York, for the study. They also took feces samples from 77 other pets that lived in the same area.

The animals’ ages, breeds, and sexes were all recorded. Then, the research team tested the samples for signs of 30 distinct kinds of aromatic amines and nicotine.

The researchers discovered that cats had at least three times the amount of aromatic amines in their urine as dogs, despite the fact that the study authors believe that both increased exposure and differences in metabolism between the two species have a role in the chemical concentrations found. Cats, in particular, do not break down many chemicals as well as dogs do.

In addition, there was little difference in aromatic amine exposure between animals who lived at home and those who lived in a shelter or stayed at a veterinary hospital, according to the investigation. This, according to Chinthakindi, emphasizes how widespread these chemicals are and how difficult it is to avoid them.

“Since pets are smaller and more sensitive to toxins, they serve as excellent ‘canaries in the coal mine’ for assessing chemical risks to human health,” says study senior author Kurunthachalam Kannan, PhD, a professor in the Department of Pediatrics at NYU Langone. “If they are getting exposed to toxins in our homes, then we had better take a closer look at our own exposure.”

Kannan, who is also a professor at NYU Langone’s Center for Investigation of Environmental Hazards, warns that it’s still unclear what quantities of aromatic amines pets may tolerate safely, and regulatory bodies have yet to set a limit for their protection.

He goes on to say that the researchers plan to look at the link between aromatic amine exposure and cancers of the bladder, thyroid, and testicles in dogs next.

Funding for the study was provided by National Institutes of Health grant U2C ES026542.