According to the Centers for Disease Control and Prevention (CDC), carbon monoxide poisoning is the leading cause of unintentional poisoning deaths in people in the United States. It is estimated that unintentional, non-fire related carbon monoxide poisoning is the reason for 15,000 emergency department visits and nearly 500 deaths annually in the U.S. 

While similar statistics may not be available regarding how many pets are affected every year, we do know that over one third of U.S. households have either a dog or cat in the home—meaning that pets are likely included in many of these poisoning cases. The ASPCA Animal Poison Control Center (APCC) wants to make sure you know how you can help protect your loved ones from this deadly toxin.

What is carbon monoxide and why is it harmful?

Carbon monoxide (CO) is called the silent killer because it is a colorless, odorless and tasteless gas—but still highly toxic.  CO impairs the oxygen-carrying capacity of the body’s red blood cells. Organs that require high amounts of oxygen, such as the heart and brain, are most affected.  

Carbon monoxide is roughly the same density as room air, so animals close to the ground are at no more risk than taller animals.  However, birds, due to their unique respiratory system are more sensitive to the effects of carbon monoxide than other animals are. 

Symptoms of poisoning may range from mild or moderate to severe and can include:

• Depression
• Vomiting
• Weakness
• Coma
• Seizures
• Dyspnea (difficult or labored breathing)
• Cardiac Arrhythmias
• Acute lung injury
• Acute Respiratory Disease (ARDS)
• Death
• Permanent deafness and blindness are also possible 

For animals who recover from carbon monoxide poisoning, monitoring should continue for at least another three to six days (or longer), for sudden worsening or return of neurological signs. Delayed neurologic effects have been reported in animals, and may have a poor prognosis.   

How do you protect your animals from carbon monoxide poisoning?

First, it is good to know what time of the year comes with the highest risk of CO poisoning, and where carbon monoxide most commonly comes from. 

Winter is the time of the year for carbon monoxide. Since home furnaces are one of the most common sources of CO, winter can increase CO emissions for many parts of the country.

Other common sources of carbon monoxide include:

• Vehicle exhaust
• Household fires
• Stoves
• Water heaters.  

The best way to keep yourself and your pets safe is by making sure you’re armed with the facts, and by taking preventive measures.

• You’ll want to ensure that your home is equipped with a carbon monoxide detector, and that it is regularly maintained.
• Never run engines in a closed area
• Keep fireplaces clean and well ventilated
• Schedule regular maintenance on your water heater or furnace on a regular basis. 

If you suspect your pet may have been poisoned by carbon monoxide, you should not waste any time, and take them into a local emergency veterinarian immediately. While this “silent killer” may sound scary, the above steps could potentially save your pet’s life. As winter approaches for many of us, it’s critical to ensure that your home is safe and sound for you and your fur family.