4. Nicotine, tobacco, secondhand smoke
Unlike many of the items on this list, nicotine is bad for both humans and pets. However, you’re probably not going to find your cat smoking a cigarette on the patio. What could happen is your dog eating stray cigarette butts and unattended nicotine gum.
Often, the pet will vomit up the nicotine if it’s a small enough amount, but it is still good to contact the vet regardless. Nicotine can influence your pet’s heart rate and cause them to have tremors and weakness. On top of that, secondhand smoke and any tobacco residue left on hands, clothing, or furniture are harmful to pets.