Ask Well Is DEET Bug Spray Harmful? Some worry that this active ingredient is toxic. Here’s what we know about its effect on human health. Eric Helgas for The New York Times Share full article ...

DEET is highly effective on humans and works to repel insects by making it harder for bugs to smell us. Although bug spray with DEET is safe for people, using it on dogs can be harmful.

Using DEET bug spray on or around dogs could cause health problems, including vomiting, lack of coordination and seizures.