Veterinarians warn that vape clouds in the home are just as harmful as regular smoke. Pets can develop allergies, coughing, and breathing difficulties, and citrus flavored e liquids are especially toxic, settling on fur, E Cigarette Toxicity Is Secondhand Weed Smoke Bad for Dogs & Cats? EarthMed Vaping at home with your pets could be making them seriously ill vet warns and could Vaping isn't just harmful to humans it's dangerous for our pets too! The aerosols from e cigarettes contain toxic chemicals and nicotine that can seriously harm pets if inhaled or ingested.