A study by the Tufts University School of Veterinary Medicine established that lawn pesticides, especially those containing the chemical 2,4-dichlorophenoxyacetic acid (2,4-D), can cause canine malignant lymphoma (CML) and canine bladder cancer. 

Contact with lawn care products applied by professional lawn companies increased the risk of CML significantly by up to 70 percent. The risk was also notably higher in homes where dog owners used self-applied insect growth regulators (chemical killing agents) on their lawns.

Exposure to these lawn chemicals and herbicides occurred through inhalation, ingestion, or skin contact. Moreover, failure to restrict dogs from recently sprayed areas increased the risk of exposure to these potentially harmful chemicals.

What is even more alarming, the studies revealed that some dogs from homes where lawn care products were not used still had traces of pesticides in their urine. It was discovered that chemicals were present in the urine of pets from 14 out of 25 homes before lawn care treatment and 19 out of 25 homes after lawn care treatment. Dogs from 4 of 8 untreated households had traces of lawn chemicals in their urine.

This means that lawn chemicals can spread from one yard to another, and inside homes. The chemicals were detected in grass residues, and they are able to drift from nearby treated lawns. Wind is the main culprit as it can carry garden chemicals up to 50 feet from the site of application.

A different study discovered that exposure to herbicides, particularly those containing 2,4-D, can also cause canine malignant lymphoma and canine bladder cancer. The risk of CML doubled in homes where dog owners applied herbicides containing 2,4-D four or more times in a year.

However, certain breeds are more susceptible to canine bladder cancer than others are. This is because of their genetic predisposition to the disease. Breeds that are at a particularly higher risk include West Highland White Terriers, Shetland Sheepdogs, Beagles, Wire Hair Fox Terriers, and Scottish Terriers.

Another study using similar research methods found herbicide 2,4-D contaminants present inside and throughout homes prior to and after lawn treatment. Considering these discoveries, the researchers concluded that pets tend to absorb and track lawn chemicals, transferring them from their intended targets.

These reports strongly suggest that environmental chemicals have far-reaching harmful effects on our health, so we need to play it safe to protect our pets and ourselves. In addition, the researchers state how their discovery can go a long way to help in the fight against human cancers.

The epidemiology and histology of Non-Hodgkin’s lymphoma is similar to canine malignant lymphoma. Moreover, the disease has strongly been linked to 2,4-D exposure, and lawn chemicals have been cited to possibly cause cancer.

Experts recommend that we should avoid using lawn care products that contain insect growth regulators. Increasing the number of foot rinses and baths along parks, streets and public highways during seasons when chemical application is highest can also help reduce the risk of exposure. We should also monitor the activity level of children and pets and encourage the removal of shoes at the door.