In a groundbreaking study, the Environmental Working Group recently tested dogs and cats for levels of synthetic industrial chemicals. It found that companion animals were contaminated with 48 of 70 toxic chemicals tested -- 43 of them at levels higher than those typically found in humans. Dogs, for example, had 2.4 times higher levels of perfluorinated compounds, which are used in stain- and grease-proof coatings and have been linked to liver damage and other health problems. Cats had 23 times the levels of fire retardants, which may be linked to thyroid problems, and more than five times the amount of mercury, a potent neurotoxin and carcinogen.

The research was based on blood and urine samples collected from 35 dogs and 37 cats at Hanover Animal Hospital in Mechanicsville, Va. in December and January. "This study shows that our pets are susceptible to the absorption of potentially harmful chemicals from our environment just as we are," said Dr. John Billeter, the veterinarian who conducted the tests. "Perhaps even more troubling is that these chemicals have been found in higher levels in pets than in humans, implying potential harmful consequences for their health and well being and the need for further study."

Under current federal law, chemical companies do not have to prove chemicals are safe before they are used in pet toys and other products for companion animals. But EWG aims to change that through a new project called Pets for the Environment. In the meantime, the initiative also offers practical tips on how to lower pets' exposure to toxic chemicals, such as doing away with flea collars and washing dogs with mild baby shampoo intended for human use rather than untested pet products.