Are Pennies Toxic to Dogs?

Name: Are Pennies Toxic to Dogs?
Creator: Dr. Zubair Khalid

By Dr. Zubair Khalid, DVM, MS, PhD · 2026-10-03

Are pennies toxic to dogs? Yes, some pennies can be. Pennies minted before 1982 are about 95 percent zinc, and that zinc can poison your dog. A swallowed penny is also a foreign body that can block the stomach or intestine, so it is a double emergency.

This article is educational and is not a substitute for veterinary diagnosis or treatment.

Quick Answer

Pennies made before 1982 contain a large amount of zinc, which can cause life-threatening destruction of red blood cells, kidney failure, heart failure, and liver damage [1][2].
Pennies made after 1982 are mostly zinc with a thin copper coating, so they can still release zinc once stomach acid eats through the plating.
A penny in the stomach is both a poison risk and a blockage risk. It may need to be removed.
Call your veterinarian, the ASPCA Animal Poison Control Center at (888) 426-4435, or Pet Poison Helpline at (855) 764-7661 right away if your dog ate a penny.
Do not make your dog vomit unless a veterinarian tells you to.

Are Pennies Poisonous to Dogs?

Yes, pennies can be poisonous to dogs, and the danger comes from zinc. Zinc is an essential mineral that dogs need in small amounts, but too much is toxic [1]. Pennies are one of the most common sources of zinc that dogs swallow.

The United States Mint changed the makeup of the penny in 1982. Pennies made before that year are roughly 95 percent zinc with a small amount of copper. Pennies made from 1982 onward have a zinc core with a thin copper plating. Both types can cause zinc poisoning, but older pennies carry far more zinc and tend to be more dangerous.

Any coin can also lodge in the stomach or intestine and cause an obstruction. That makes a swallowed penny a toxicity emergency and a foreign body emergency at the same time. If your dog ate a penny, treat it as urgent even if your dog seems fine right now.

What Is the Toxic Principle and What Does It Do?

The toxic principle is zinc metal. When a penny sits in the stomach, stomach acid breaks down the metal and releases zinc [1][2]. That zinc is absorbed into the bloodstream.

Once in the blood, zinc damages red blood cells. It causes oxidative injury that destroys red blood cells, a condition called hemolytic anemia [1][2]. When red blood cells burst, the dog loses the cells that carry oxygen. This can lead to weakness, pale gums, a fast heart rate, and organ damage from lack of oxygen.

Zinc poisoning in dogs is linked to several serious problems. These include gastrointestinal upset, pancreatitis, hemolytic anemia, and acute kidney failure [3]. It can also lead to kidney and heart failure and liver damage [1][2]. In severe cases, the damage can be fatal.

One case report described a dog with zinc poisoning that also developed a blood condition called methemoglobinemia, which makes it harder for the blood to carry oxygen [3]. That dog went on to develop multi-organ dysfunction and ultimately died [3]. This shows how quickly and how widely zinc can harm the body.

Signs of Zinc Poisoning in Dogs and the Timeline

Signs can start within hours of swallowing a penny, or they may take a day or more to appear. The timeline depends on how much zinc the coin releases and how long it stays in the stomach.

Early signs often involve the gut. Watch for:

Vomiting
Loss of appetite
Diarrhea
Lethargy or weakness
Abdominal pain

As red blood cells are destroyed, more serious signs can appear:

Pale gums or white gums
Yellowing of the gums, skin, or eyes (jaundice)
Dark or brown urine
Fast breathing or fast heart rate
Collapse
Seizures or tremors

Because the penny can also block the intestine, you may see vomiting that will not stop, a swollen belly, or a dog that cannot keep anything down. Some dogs show no signs at first, which is why a swallowed penny always needs veterinary attention.

What to Do Right Now If Your Dog Ate a Penny

Act quickly. Time matters with zinc poisoning.

Remove your dog from any other pennies or coins.
Call your veterinarian right away. If your regular clinic is closed, call an emergency veterinary hospital.
Call the ASPCA Animal Poison Control Center at (888) 426-4435 or Pet Poison Helpline at (855) 764-7661. These services can guide you and your vet.
Do not induce vomiting unless a veterinarian tells you to. Making a dog vomit can cause problems, and a penny can get stuck on the way up.
Do not give food, milk, or home remedies unless a veterinarian instructs you.
Bring the coin wrapper or any information about the penny if you know it, and note the time your dog swallowed it.

If you are not sure whether your dog actually ate a penny, call anyway. It is better to be told your dog is fine than to wait while zinc is being absorbed.

For a broader look at what to do after any suspected poisoning, see What to Do If Your Dog Ate Something Toxic: First Aid Steps.

How Veterinarians Diagnose and Treat Penny Poisoning

Your veterinarian will start with a physical exam and questions about what your dog ate and when. They may take X-rays to look for the penny in the stomach or intestine. Pennies often show up clearly on radiographs.

Blood work helps the vet check for anemia, organ damage, and changes in the blood. They may also check for methemoglobinemia, since this has been reported in dogs with zinc poisoning [3].

Treatment depends on where the penny is and how sick your dog is.

If the penny is still in the stomach and it is safe to do so, the vet may induce vomiting or remove it with an endoscope.
If the penny has moved into the intestine or is causing a blockage, surgery may be needed.
If zinc has already been absorbed, treatment focuses on supportive care. This can include intravenous fluids, medications to protect the stomach, and blood transfusions for severe anemia.
Some dogs need oxygen therapy and close monitoring in the hospital.

Your vet calculates any medication dose from your dog's weight and health. Never give human medicines or supplements on your own.

Outlook for a Dog That Ate a Penny

The outlook is good when the penny is removed early and before serious damage occurs. Many dogs recover fully with prompt treatment.

The outlook is more guarded when zinc has caused severe hemolytic anemia, kidney failure, or multi-organ damage. Severe zinc poisoning can be fatal [3]. The longer the penny stays in the stomach, the more zinc is released and the higher the risk.

This is why you should never wait to see if a penny passes on its own. Some coins pass through without causing harm, but others release enough zinc to poison a dog [1][2]. You cannot tell which will happen, so a vet visit is the safe choice.

Preventing Penny Poisoning and Safer Alternatives

Prevention is simple and effective.

Keep loose change out of reach. Store coins in closed containers, not on counters, tables, or floors.
Check under couch cushions, in laundry baskets, and in bags where coins collect.
Teach children to keep pennies away from dogs.
Pick up dropped coins right away.
Supervise your dog around areas where coins might be found.

If your dog likes to chew or swallow objects, talk to your vet about safe chew toys and enrichment. A dog that chews on metal objects is at risk for other foreign bodies too. For more on swallowed objects, see My Dog Ate a Pen: Is It Toxic or Just a Blockage Risk?.

Other household items can also poison dogs. Foods are a common culprit. Learn more in Foods Toxic To Dogs Pdf and How Much Chocolate Can Be Toxic To Dogs.

Limitations and When to Contact a Veterinarian

This article gives general information. Your dog's case is unique, and only a veterinarian who examines your dog can give you specific advice.

Contact a veterinarian the same day if:

You saw your dog swallow a penny.
You found a chewed or missing penny.
Your dog is vomiting, has diarrhea, or seems tired.
Your dog's gums look pale or yellow.

Go to an emergency veterinary hospital right away if:

Your dog collapses or is very weak.
Your dog has trouble breathing.
Your dog has a swollen, painful belly.
Your dog has seizures or tremors.
Your dog's urine is dark or brown.

Schedule a routine visit if your dog has a habit of eating coins or other objects. Your vet can help you with prevention and behavior advice.

Frequently Asked Questions

Are all pennies toxic to dogs?

No, but any penny can be risky. Pennies made before 1982 contain much more zinc and are more dangerous. Pennies made after 1982 have a zinc core, so they can still release zinc once stomach acid breaks through the copper coating.

How long after eating a penny will my dog get sick?

Signs can start within hours, but some dogs show no signs for a day or more. The timeline depends on how much zinc is released and how long the penny stays in the stomach. Do not wait for signs to appear before calling a vet.

Can a penny pass through my dog on its own?

Sometimes a coin passes in the stool without causing harm, but you cannot predict which coins will do that [1][2]. A penny can also get stuck and cause a blockage. A vet can check with an X-ray to see where it is.

Will my dog be okay if the penny was minted after 1982?

Not always. Newer pennies have a zinc core, and stomach acid can eat through the thin copper plating and release zinc. The risk is lower than with an older penny, but it is still a medical emergency that needs a vet.

Can I make my dog throw up the penny at home?

No. Do not induce vomiting unless a veterinarian tells you to. Vomiting can cause the penny to get stuck in the esophagus, and some dogs should not vomit for other health reasons. Call your vet or a poison control line first.

References

Is Zinc Toxic to Dogs. Pet Poison Helpline.
Is Zinc Poisonous for Dogs. Pet Poison Helpline.
Methemoglobinemia Secondary to Zinc Foreign Body Ingestion in a Dog. Journal of veterinary emergency and critical care (San Antonio, Tex. : 2001), 2026.