Wild pigs in the US are turning a colour only comparable to Cool Blue Gatorade.
California is home to some 400,000 feral hogs, but game hunters say the insides of wild pigs they have killed this year are a neon blue.
Dan Burton, who owns a wildlife control company, told the Los Angeles Times that he found a discoloured swine in Monterey County in March.
He trapped some wild pigs which had been nibbling the crops of an agriculture firm, only to see their insides were a slushie blue when he cut them open.
‘I’m not talking about a little blue,’ the Salinas local said. ‘I’m talking about neon blue, raspberry blue.’
Blue pigs, however, are nothing new. A user on the image-sharing website, Imgur, shared photographs of a ‘weird pig’ in 2015.
‘My in-laws live on a ranch in Morgan Hill, [Santa Clara County], and they shot a wild pig on it. They thought it was a normal pig until they cut it open,’ they wrote.
While their in-laws do live near an abandoned mercury mine – copper poisoning can tint flesh blue – the user said they’ve shot pigs before and not seen them have blue fat.
They added: ‘Everything else about the pig was normal, the meat, blood, etc. The only weird part was the blue fat throughout the body.’
Burton alerted the California Department of Fish and Wildlife, which confirmed the pig had ingested diphacinone, a slow-acting poison.
Diphacinone is used by farmers to keep squirrel, rat and mice populations in check, placed in bait stations for the critters to eat.
When consumed, the ‘extremely toxic’ chemical stops blood from clotting, causing heavy internal bleeding, fever and back pain, according to a government fact-sheet.
Pest control companies dye the coffee bean-shaped substance blue to make it clear to humans that it’s a rodenticide.
But pigs can’t read warning labels – state wildlife officials found the poison in a pig’s stomach and liver, suggesting the hogs have been eating diphacinone out of bait stations.
Wild pigs, a cross between domestic pigs and wild boars, are omnivores, so they may be eating both the poisoned rodents as well as the bait.
The surreal blue hue of the pig meat isn’t because of the rodent control itself but rather the dye, which leaks into the animal’s muscles and fat.
This bizarre side-effect happens when an animal consumes a large quantity of diphacinone, meaning that even if a pig appears juicy and red inside, it may still have ingested some of the poison.
People and predators who eat meat painted blue by the poison can suffer ‘secondary exposure’ because the substance can remain in the animal’s system for weeks, studies have found.
Cooking the discoloured meat does little to decrease the concentration of the poison.
Burton said that he found the blue pigs he found had been eating from squirrel bait stations.
Given that it takes days for the poison to take effect on small animals, let alone 91kg pigs, he said that may be why the swine appeared perfectly fine.
Diphacinone has been mostly prohibited across California since 2024, usable only by certified pest control staff, government officials or at farms.
Wildlife officials are now warning hunters, trappers and anyone who eats wild pig to stay away from blue coloured meat.
Anyone who comes into contact with blue hogs is urged to report it to the agency.
No other blue-tinged animals have been reported in Monterey County since March.
Researchers in 2018 found that nearly one in 10 wild pigs living near human-controlled areas was contaminated with rodenticide.
CDFW pesticide investigations coordinator Dr Ryan Bourbour said in a statement: ‘Hunters should be aware that the meat of game animals, such as wild pig, deer, bear and geese, might be contaminated if that game animal has been exposed to rodenticides.
‘Rodenticide exposure can be a concern for non-target wildlife in areas where applications occur in close proximity to wildlife habitat.’
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