Mothballs And Dogs. Mothballs contain a high concentration of insect repellent. Pets who are around mothball fumes may develop red, runny eyes, a runny nose, sneezing, and/or coughing.
Are mothballs dangerous to cats and dogs? Mothballs contain a high concentration of insect repellent. Solid pesticides at room temperature containing highly volatile chemicals, they emit toxic fumes.