Deadly Lawns

Your dog loves to go for walks. He stops at every tree, shrub and weed to “read the news” of his neighborhood. But these happy times can be dangerous to your friend. Sadly, chemically treated lawns are a reality of suburban life and many animal guardians do not realize how toxic a treated lawn can be. Every time your dog sets foot on a treated lawn, whether freshly sprayed or dry, he or she is being exposed to environmental toxins like pesticides and herbicides.

Most dogs love a carpet of thick green grass. They smell it, run around on it, roll on it and dig at it. We launder our clothes and bathe regularly, but dogs don’t shower every morning or change their fur and footpads every day. So, whatever collects on their feet or coat stays there until the next time you give them a bath. Every time your dog licks his paws or stomach - anywhere that touched a treated lawn - he is ingesting chemical residue. As he smelled the lawn, he inhaled it and as the chemicals settled in his fur, they were absorbed through his skin. When your dog comes inside, the chemicals are deposited on multiple surfaces in your home, including carpeting, rugs, furniture and your dog’s bedding. When your dog's outdoor environment has been doused in potentially toxic chemicals, it is easy to see how normal canine behavior can turn to deadly risk.

It is also clear that there is chemical drift. Toxic chemicals are commonly detected in grass residue from untreated lawns. This means that even if you don't use lawn care products or a service, your dog could still be at risk from chemicals that blow into your yard from a nearby property.

If you think your dog has rolled on chemically treated grass, bathe her as soon as possible. If you've walked your dog in a suspect grassy area, giving her a foot soak as soon as you get home should flush away any chemical residue that may be clinging to her feet and lower legs. If your dog is low to the ground, wash her belly, chest and tail too.

Contrary to what lawn care companies would like you to believe, herbicides (weed killers) and other pesticides are not "magic bullets" or programmed drones that kill only targeted species. Herbicides and pesticides are broad-spectrum biocides that by their very nature can harm all organisms, including homeowners, their families, neighbors, animals, both wild and domestic, and all other forms of life. The pesticide industry downplays this by claiming their chemicals are heavily diluted, but doesn't mention that the toxins are still extremely dangerous, even in small amounts. The industry is also unwilling to mention all of the chemicals in their mixtures. Many components are classified as "inert", but inert does not mean inactive. These components are more than just fillers or solvents, but companies are not required to list inert components on product labels, thus leaving the public unaware of them. Some, such as benzene and xylene, are more toxic than the chemicals actually listed.

Active ingredients in lawn care products can be nerve-gas type insecticides and artificial hormones, some of which the federal government has even prohibited from use on its own properties. Also among the listed active chemicals are the components of defoliants like Agent Orange. This now infamous defoliant was used during the Vietnam War to destroy forest cover for the enemy and also their food crops. Agent Orange has since been revealed to cause a wide range of serious health issues, including rashes, psychological problems, birth defects and cancer. During WWII, a pesticide was developed known as 2,4-dichlorophenoxyacetic acid, or "2,4-D. This chemical was one of two active ingredients in Agent Orange. Yet, 2,4-D is still used on athletic fields, golf courses, landscaping, timberland, right-of-ways and various crops. Despite decades of scientific studies associating 2,4-D with cancer in humans and animals, the chemical continues to be one of the top-three pesticides sold in the U.S. More recent studies have linked the chemical to hormone disruption that increases the risk of birth defects and neurologic damage in children.

Many pesticides are not safe even when dry. The water in lawn care solutions may evaporate, but most pesticides remain and continue to release often odorless and invisible toxic vapors. In areas where lawn spraying is common, these vapors accumulate as toxic smog throughout the entire season. Exposure to pesticides is widespread. The US Center for Disease Control and Prevention (CDC), in a study of 9,282 people nationwide, found pesticides in 100% of the people who had both blood and urine tested. The average person carried 13 of 23 pesticides tested. We do not have similar data for companion animals, but it is easy to imagine a similar result.

Common groups of lawn pesticides and their effects on animal health include:

  • Organophosphates: Organophosphate compounds include some of the most toxic chemicals used in agriculture. Fat-soluble and easily transmitted throughout the body, this group of pesticides is defined by their inhibition of the enzyme cholinesterase. Examples of this class of chemicals are Chloryprifos and Diazinon. Poisoning symptoms in animals include excessive salivation, "wet" respiratory sounds (because of increased bronchial secretions), vomiting, abdominal pain, diarrhea, slow heart rates and miosis (pinpoint pupils). In serious cases, respiratory failure and death can occur.
  • Carbamates: Carbamates cause a reaction similar to organophosphates because they inhibit the same enzyme pathway. This group includes the commonly used insecticide carbamyl. Exposure causes convulsions, dizziness, labored breathing, nausea, vomiting, diarrhea, unconsciousness, muscle cramps, and excessive salivation. Toxicity of these chemicals depends on the path of exposure.
  • Phenoxy: Phenoxy and benzoic acid herbicides like 2,4 D, MCPP, and MCPA affect the central nervous system. Poisoning symptoms include involuntary twitching, loss of sensation, vomiting, stomach pains, diarrhea, weakness, fatigue, dermatitis, and aching muscles. Dogs and cats that don’t excrete acids as efficiently are especially sensitive to this chemical. An EPA-funded study found that 2,4-D is easily tracked indoors, exposing children and animals at levels ten times higher than pre-application levels. Another study showed that exposure to phenoxy-treated lawns and gardens appeared to dramatically increase the risk of bladder cancer in Scottish Terriers.
  • Pyrethroids: Pyrethroids are listed as possible carcinogens by the US EPA and affect the central and peripheral nervous systems. Commonly used chemicals like Permethrin and Resmethrin are in this group. Poisoning symptoms include muscle tremors, hyperexcitability, depression, ataxia, vomiting, seizures, anorexia, and death. Exposure to Resmethrin caused increased thyroid and liver weight in adult dogs, and exposure to these chemicals is linked to harm in neurological development.

What You Can Do

Protecting Your Animal from Toxic Pesticides
  • Don't apply pesticides to your yard, and if you use a lawn care service, don't allow them to use pesticides. Weed killers are herbicides and no herbicides are safe. Also avoid lawn care and other gardening products that contain insect growth regulators (IGRs).
  • If you live in a townhouse or community that applies chemicals to common areas, detox a patch of grass in your backyard by watering the chemicals down into the soil. If you can’t keep your animal on a leash (and on the sidewalk) when walking, then bathe, bathe, bathe.
  • Freshly treated lawns are the most toxic. Twenty-one states have adopted laws requiring notification of lawn, turf and ornamental pesticide applications by hired applicators. They must post signs on treated lawns to let neighbors and passersby know that chemicals have recently been used.
  • There are alternatives. You can still have a beautiful lawn without the use of dangerous chemicals. Optimize growing conditions in your lawn by following lawn care practices that will establish a healthy, dense lawn, one that will be naturally resistant to weeds, insects and diseases.
Improve the Soil
  • Test - The first step is to test the soil's pH. It should read between 6.5 and 7.0, which is slightly acidic. Soil that is too acidic will need a sprinkling of lime. Sulfur can be added to soil that is not acidic enough. You can buy a pH tester for $40 - $60 or have your soil tested. Call your extension office. They will often provide soil testing as a free service.
  • Aerate - Lawns grow best in loamy soils that have a mix of clay, silt and sand. Too much clay in the soil mix can compact the soil and prevent air and nutrient flow. Compacted soil may need aeration, a process of lifting small plugs of turf to create air spaces. For best results, rent an aerator or hire a lawn service to do the job. Aeration is best done before top dressing and fertilizing.
  • Add organic matter - Organic matter, such as compost and grass clippings, will benefit any type of soil. It lightens soil heavy in clay and builds humus in sandy soils to help retain water and nutrients. Use a mulching lawn mower that chops the grass clippings and disperses them as you mow. Grass clippings are high in nitrogen.
  • Choose a locally adapted grass - Grasses vary by the type of climate they prefer, the amount of water and nutrients they require, their shade tolerance and the degree of wear they can withstand. Ask your local garden center to recommend the grass best adapted to your area.
  • Mow often, but do not cut too short - Giving your lawn a "Marine cut" is not doing it a favor. Surface roots become exposed, the soil dries out faster and surface aeration is reduced. As a general rule, don't cut off more than one-third of the grass at any one time. Most turf grass species are healthiest when kept between 2.5” and 3.5" tall. When the lawn is finished growing for the season, cut it a bit shorter to about 2". This will minimize the risk of mold buildup during winter.
  • Water deeply but not too often - Thorough watering encourages your lawn to develop a deep root system that makes it hardier and more drought-resistant. Let your lawn dry out before watering. As a rule of thumb, the color should dull and footprints should stay compressed for more than a few seconds. When watering, put a cup in the sprinkler zone. The cup should collect at least one inch (2.5cm) of water. Most healthy lawns require only 1" of water per week. The best time to water is early morning, when less water will be lost to evaporation. Ideally, it is better to water the first half-inch or so, then wait for an hour or two before watering the second half-inch.
  • Control thatch build-up - Thatch is the accumulation of above-soil runners, propagated by the grass. This layer should be about 1/2" (1.25cm) on a healthy lawn, and kept in balance by natural decomposition, earthworms and microorganisms. Too much thatch prevents water and nutrients from reaching the grass roots. However, before resorting to renting a dethatcher, effort should be made to improve aeration. Aeration brings microorganisms to the surface that will then eat most of the thatch. If you don't aerate, the roots stay near the surface, contributing to thatch buildup. When you aerate once a year, it breaks down the thatch, allowing the roots to grow deeper in the soil. This leads to thicker grass, which naturally smothers weeds. While a dethatcher will reduce thatch buildup, be careful not to strip and thin the grass so much that it reduces competition between the grass and weeds, allowing the weeds easier germination. You can also reduce thatch with a steel rake.
The dangers outside your door are not always obvious. Stay informed and share this information with friends and family. Being an animal advocate can be as simple as spreading the word about an issue like lawn care toxicity. You are your companion’s guardian. Protect them and use your voice to help protect them all.