NEWS:   A California Reddit user claimed his in-laws shot and butchered a pig with blue fat.

On 9 September 2015, Reddit user GlendilTEK published an image gallery named “The Weird Pig,” accompanied by a thread in the subreddit r/whatisthisthing titled “My in-laws shot a wild pig on their ranch in Morgan Hill, California. The weird part is that the pig has fluorescent blue fat. Does anyone know how or why the fat could be this color?”

The gallery and its companion thread included five photos of the anomalous purported carcass:

So, my in-laws live on a ranch in Morgan Hill, CA and they shot a wild pig on it. They thought it a normal pig until they cut it open. (Just to clarify since there has been questions they did not start cutting open the pig until they had strapped it to the ATV and driven back home so most of the blood has left the pigs body at this point.)

When they cut into the pig they found that the fat on the pig was a fluorescent blue. (I know blue pigmentation is often caused from copper poisoning but all that they have are some old mercury mine shafts that they have filled in. They have also shot wild pigs on the ranch before and none of them have been blue.)

Everything else about the pig was normal, the meat, blood, etc. The only weird part was the blue fat throughout the body.

We have no clue why the fat is this color but it is all over the pig no matter the section.

They are sending in a sample to UC Davis to see the cause of this, but if anyone knows please feel free to explain because we are at a loss.

The photographs didn’t appear to have been previously published online with a different attribution, and all instances of their existence on the web occurred after the above-linked Reddit thread. As such, it wasn’t likely the poster fabricated a clever backstory for interesting photographs he had discovered elsewhere online. The authenticity of the images wasn’t immediately determined, but fellow Reddit users reported witnessing the phenomenon in the past and in the same locality. For example, Reddit user sheep_wrangler replied:

Yep! Hunted pigs in Morgan Hill, CA where this was shot. We used to poison the ground squirrels with anticoagulant rodenticide which was dyed blue. I guess they are teaching this in hunters safety according to another CA hunter. “If the meat is blue, it is not for you!” But Ive shot a few pigs that had that color but not even as close to that vibrant of a blue. But yea its because of a poison we used on ground squirrels!

The anticoagulant to which the user referred appears to produce a similar “blue fat” effect in squirrels. A user who self-identified as an ecologist provided a possible name for the anomaly and surmised that the pig ingested a substance that was fat soluble:

This is called “blue pig syndrome” and was first found in Uganda in 1998. Tests at the Makerere University Faculty of Veterinary Medicine and a veterinary reference laboratory in Pirbright, UK, could not establish the cause of the syndrome by 2013 and as far as I know it is still a mystery today. There is also a discussion on Research Gate about it.

Considering this pig is in California it’s likely it has been ingesting water from a local food or candy factory making blue dyes for their food. Some folks are suggesting the pig drank from a Port a John, but given the side effects I am not sure it would have really done this … Someone mentioned Anticoagulants put down to kill ground squirrels which are pests in California. I think this is the most likely culprit.

According to the user who submitted the photos, testing on the pig’s remains was not yet complete:

Just a quick pseudo update. They have not heard back on the results, but have let the carcass sit for about a day, no animals seem to touch it or try to eat it which was interesting. Also, they reached out to there neighbors and no one mentioned any dying of food, but I will ask them if they will ask specifically about it. Lastly, they do have some old mercury mine shafts on the ranch, but those are filled in. They have also shot wild pigs before on their property and they have not been blue. I hope this extra info helps and thank you for all the theories and help! Edit: sorry if this isn’t the proper way to update a post I’m a tad new to posting to reddit and don’t yet know how to do things.