Canines-Sentinels to Environmental Pollution

Anne Jones RN, BSNE, edited by Mayno Blanding

The title, Polluted Pets (see * below), is intriguing; the first sentence alarming. The article was forwarded to the Health Committee by a concerned breeder/exhibitor, believing it would be of interest to breeders and pet owners. It seems appropriate to share a summary and to allow each reader to make his/her own assessment. It does serve to add to concerns regarding overuse of pesticides and excessive use of vaccines in dogs.

The Environmental Working Group (EWG) that wrote this article uses the slogan “THE POWER OF INFORMATION” as a clue to its function. Since the article comprises some 18 pages, about half of which are references, the purpose here is to summarize the information therein.

EWG, with the assistance of a Virginia veterinary clinic, collected urine and blood samples from 20 dogs and 37 cats and found them to be contaminated with 48 of 70 industrial chemicals for which they tested, most of them in higher levels than normally found in humans. This paper will address primarily the results in dogs, but cats show a greater level than dogs in many instances, possibly due to their grooming habits. Chemicals found were in three categories – plasticizers, greaseproof chemicals and fire retardants.

Companion animals offer an advantage in research by virtue of their short life span. Animals have long been the guardians of our safety, going back to the use of canaries in mines to warn of poisonous gases. The chemicals that exist in their environment are in direct correlation to our own, because they live in our homes and play in our yards. Average levels of these chemicals were often found to be much higher in pets than in humans, with dogs 2 1/2 times as high in stain and grease proof coatings (often higher) and cats having 23 times more fire retardants and 5 times more mercury (fish diets?).

Dogs were contaminated with 35 chemicals that included 11 known carcinogens, 31 known to be toxic to reproductive systems, and 24 neurotoxins. Researchers are already aware that dogs are showing increasing incidence of cancers, based on studies at respected veterinary institutions, yet health risks to pets are only beginning to be noted and researched in terms of environmental exposure.

The dogs tested included both mixed breeds and purebreds, ranging in size from toys to large breeds and in age from 6 months to 12 years, with 12 females and 8 males. The chemicals were found on average to be at levels 5 times higher than levels typically found in humans. Chemicals found were classified as stain- and grease-proof chemicals in the Teflon family, phthalates found in plastics, and fire retardants known as PBDEs.

Teflon chemicals were at the highest level. The product used to coat pans was at about the same level as in humans. The likely source of the greater contaminant is that form of teflon chemical used in dog food bags to coat them and in products in the home to stainproof furniture (and dog beds?). It would also be shed as house dust.

Plastic softeners are used in toys, plastic containers and wraps (shower curtains – think of that smell!), shampoos and other household products. They can be dangerous to the reproductive system, carcinogenic and cause birth defects. They are also likely to exist in house dust.

Fire retardants are used in bedding (including foam) and clothing and can be found in house dust and in food. Manufacturing changes are in effect since 2005 but they still are around and will be for many years. These chemicals are known to affect thyroid hormone function and may affect brain development.

Because many of these byproducts exist as dust and in other forms (for instance, they are in our streams), they can also be found in foods, especially seafood, due to existing environmental contamination.

What are the health risks to companion animals? These chemicals exist and will exist in air, soil and water for many, many years to come. Careful cleaning of the home, use of environmentally safe cleaning products, minimal use of pesticides – and only those tested for safety in animals – can help. Clean and safe water is important because dogs need to have a ready supply of FRESH water. Stale water is not appealing but, more to the point, it may be coated with dust from sitting on the floor where dust is constantly stirred up. Food storage should be in safe containers and covered for the same reason.

The greatest long-term protection for animals will be aided by greater protection for mankind. Pet owners should be aware of food quality and avoid cheap ingredients that may cause harm. Oversight is key for both humans and animals; food sources should be regulated and inspected to ensure regulations are observed. Pet owners should have greater concern about the use of chemicals in pesticides, cleaning products and in manufacturing. While this was a very limited study, it does highlight the need for increased understanding of environmental issues for pets and humans alike.

* “Polluted Pets”, published by Environmental Working Group; April 17, 2008 www.ewg.org/research/polluted-pets