Here’s what you'll learn when you read this story:

• For years, scientists have kept a close eye on the animals around the Chernobyl Nuclear Power Plant in the hopes of learning from the one-of-a-kind accidental radiation exposure experiment currently in progress.
• One of the most talked-about groups of test subjects is the wild dogs that live around or near the power plant, which have been shown to be genetically diverge from similar dog populations in eastern Europe (though the cause of that divergence is still uncertain).
• Recent videos of blue-hued Chernobyl dogs caused a bit of a stir online, until it was confirmed the dogs had just been rolling around in porta-potty chemicals.

On April 26, 1986, Chernobyl Nuclear Power Plant near Pripyat, Ukraine, exploded—a combination of poor reactor design and serious mismanagement had caused the worst nuclear disaster in human history. Fast forward 40 years, and things have changed.

While the horrific death, illness, and environmental degradation caused by the meltdown will never be completely forgotten, the area surrounding Chernobyl has come to provide a rare scientific opportunity. Today, it is a living laboratory for scientists exploring questions (many of them genetic) regarding long-term exposure to high levels of radiation.

Frogs, for example, have adapted darker skin colors to protect against radiation. Barn swallows within the Chernobyl Exclusion Zone (CEZ) displayed bent tail feathers, deformed air sacs, and misshapen beaks. Elsewhere, wolves in the area have proven surprisingly resistant to cancer, especially for a top predator. But the real test-subject mascots of the CEZ are undisputedly the stray dogs.

According to the official group Dogs of Chernobyl—which captures these strays, vaccinates them, and tags them—many of today’s Chernobyl dogs are the descendants of abandoned pets of the evacuated residents that were living in the area, but never allowed to return.

The group says that some 250 dogs roam the Chernobyl Plant, while another 225 or so live in nearby Chernobyl City. Famously, they’ve also been the subject of scientific studies comparing their genomes to control populations near the CEZ but not impacted by historical radiation levels.

While they found that the dogs did display genetic differences from other populations, chalking those differences up to radiation isn’t so easy. One explanation, according to a 2024 study, could be a simple case of genetic drift—where an isolated population begins to exhibit preferences for certain traits over others in a way that differs from other populations.

With all of this in mind, it makes sense then that when pictures of blue Chernobyl dogs began circling online in fall 2025, it raised more than a few eyebrows. Could this bluish hue finally be the stunning visual evidence that accumulated genetic changes have impacted the Chernobyl dogs’ appearance?

“We are on the ground catching dogs for sterilization and we came across three dogs that were completely blue,” the non-profit organization Clean Futures Fund, which posted videos of the blue dogs on Instagram, said in a caption. “We are not sure exactly what is going on. The town people were asking us why the dogs were blue? We do not know the reason and we are attempting to catch them so we can find out what is happening.”

While the Chernobyl dogs may be genetically different from their Eastern European canine neighbors, they are most likely blue for a very dog-like reason: They rolled around in some gross chemical stuff. Speaking with the website Storyful, the nonprofit surmises that the dogs somehow accessed a leaking porta potty and rolled around in the blue dye. Other than their strange coloring, the dogs are otherwise active and healthy.

While dogs of Chernobyl may be one of the most famous pack of wild dogs in scientific history, at the end of the day—dogs will be dogs.