Woman shocked to find her dog's fur turned green overnight

There are many fun surprises to wake up to when you own a dog – missing socks, chewed-up furniture, but rarely does 'green fur' crack a mention.

One woman was shocked after she brought her dog Olive home from the vet after a procedure — waking up the next day to find that the fur around the plastic cone on her head had turned green.

Taking to Twitter Dr Stephanie Olson, a geoscientist at the Purdue University Department of Earth, Atmospheric, and Planetary Sciences in Indiana, USA, documented the reason why her dog went from show dog to grinch overnight.

Admitting she was "alarmed" at the bizarre change in colour, the Earth geochemist was determined to find out what happened to Olive's fur.

A photo of a dog with a cone on its head, looking upwards showing the green fur under her chin.
Dr Olson was determined to find out why Olive's fur turned green. Source: Twitter/ Dr Stephanie Olson

The answer was in the drool

Like every good story, it begins with a lot of drool.

"Usually it ends up on my floors and walls or the pants of visitors," Dr Olson explained. "But while Olive is recovering from surgery, her cone collects and funnels her juices down her neck."

She went on to explain that dog saliva contains iron porphyrins which upon contact with oxygen, oxidises to iron oxide nanoparticles, or essentially rust.

"This is why Olive and many other drooly dogs have rusty, red staining by their mouths," she said, adding that due to the positioning of the cone, Olive had to sleep with her chin flat on the ground, allowing the salvia to pool underneath her and down her neck.

"She was sedated and slept like a rock, but her saliva bacteria got to work," the scientist explained. "They quickly consumed all of the oxygen in her neck swamp, which prevented the red staining typically associated with dog saliva."

"Instead, green rust formed!"

Green rust is rare today

According to Dr Oslon, green rust usually occurs in low-oxygen environments.

"Green rust is rare today because it is unstable in the presence of oxygen, but it may have been common on the ancient Earth before our atmosphere became oxygenated," Dr Olson explained. "The ocean may have even appeared green instead of blue 2.5 billion years ago!"

"Alternative hypothesis: Olive is actually short for Olivine, a famously green mineral, and she is just honouring her namesake," she joked at the end of the thread.

Do you have a story tip? Email:

You can also follow us on Facebook, Instagram and Twitter and download the Yahoo News app from the App Store or Google Play.