Which color indicates carbon monoxide poisoning?

• A. Pink
• B. Blue
• C. Cherry red
• D. Yellow

Answer: (C)

Cherry red is the telltale color in carbon monoxide poisoning. Carbon monoxide binds tightly to hemoglobin to form carboxyhemoglobin, which gives blood a bright red color. This reddening can be seen on the skin and mucous membranes (like gums and lips) and is classically described as cherry red. Blue would indicate cyanosis from inadequate oxygen delivery, which isn’t the typical color sign for CO poisoning, and yellow isn’t associated with this condition. Pink can be related to a lighter red hue, but cherry red is the classic indicator clinicians look for. If you suspect CO poisoning, it’s an emergency and requires removing the animal from exposure and seeking veterinary care promptly.