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How dogs can turn green (or brown) overnight 🤯

Jul 22, 2021

How dogs can turn green (or brown) overnight 🤯

This Saint Bernard already had a cone of shame to deal with. And then overnight she turned green. Here’s how it happened and why your dog might just do the same. Hint: It’s all about the drool…

Sometimes life is all about Drool. And that’s certainly what Olive the Saint Bernard’s pet parent, Dr Stephanie Olson discovered when she woke up to find her dog’s neck glowing green after being a very normal skin colour the night before. Importantly, Olive only had the cone on her head to prevent her chewing out stitches from an operation. Yet, this phenomenon is completely unrelated to that surgery.

The answer to this mystery comes back to a quirk of our pet’s drool…and tears for that matter too. They contain iron. Yep that good old metal that creates steel. Yet, when these tiny iron molecules are exposed to oxygen in the air, they rust. That’s the fascinating reason why dogs with itchy, allergic skin often wake up with brown discoloured fur on their feet or bellies or why drooly dogs often have brown marks around their mouths. They’re essentially rust stains. But that doesn’t explain the green colour!


But here’s what happened. By Olive having the cone of shame on her head, it caused all that drool to gather and pool around her neck. Yet, by having the plastic cone sitting on her neck, it prevented the oxygen in the air reaching the drool. So instead of red/brown rust, a special type of low oxygen green rust formed simply from the lack of air. Steel that’s partially submerged in water does the same thing.

Sure most dogs change colour after consuming permanent markers or rolling in something at the park they really know they shouldn’t! But Olive really stepped up here with something highly original and very appropriate to her name. Onya Olive.

(Pics: Stephanie Olson)