Secondhand (and Third Hand) Smoke May Be Making Your Pet Sick McCleary Animal Hospital One of our customers has had first hand experience of this recently. One cigarette butt can contain enough nicotine to poison a dog. Especially puppies and smaller breeds. What can happen The Effects of Secondhand Smoke on Pets PetMD Don't Puff Around Pets American Lung Association Second Hand Smoke Around Pets The Grey Muzzle Organization