Your home can unknowingly be a dangerous place for a pet.

Even the simplest objects can cause serious trouble if your dog swallows—or sometimes even licks it or chews—on them. Here are seven common household items you shouldn't leave laying around. If you think your pet has been in contact or swallowed any of these, contact your veterinarian immediately.

Batteries

Batteries are one of the most dangerous things your pet can have access to. If bitten, the acid inside the battery can cause pain and burns to the mouth, vomiting, and excess salivation. If ingested, a battery can cause an intestinal obstruction that might require surgery. Ingestion of a battery is always an emergency and you should see your vet right away.

Mothballs

Your pet doesn't have to ingest a mothball to be in trouble—even the fumes produced by them can cause serious problems. Naphthalene, a chemical found in mothballs, can be absorbed through the skin and lead to additional health issues. Common side effects of exposure to mothballs include vomiting, lethargy, gastrointestinal distress, and weakness. More serious symptoms include seizures, tremors, and liver damage. Fumes can cause serious eye and nose irritation. Although cats are more sensitive to mothballs than dogs, both can suffer poisoning effects from exposure.

Firestarter Logs

Firestarter logs may contain heavy metals, which are toxic to both dogs and cats. "Along with toxicity, your pet may chew or eat the log, which has the potential to cause an obstruction," says Laurel Birmingham, Director of Veterinary Health at Pasadena Humane Society in Pasadena, California. The logs are usually made of compressed wax and sawdust, which doesn't break apart or dissolve easily.

Coins

Certain types of coins contain zinc, which can be toxic if ingested. Zinc is especially high in Pennies and can also be found in other metallic items, such as screws. "Coins can also cause internal obstructions," Birmingham says.

Dental Floss

According to Birmingham, the biggest risk with rubber bands or dental floss is that they can tie around your pet's intestinal tract and cause an obstruction. "If you rush your pet the veterinarian immediately, they may be able to induce vomiting and avoid an obstruction," Birmingham points out.

Magnets

Magnets are especially dangerous if your dog swallows more than one, as they will attract each other, catching small pieces of the intestine in between them. This might lead to tissue dying or to intestinal perforation. Bacterial infection is also a possibility.