In recent weeks, photos claiming to show “blue dogs” roaming the Chernobyl Exclusion Zone have gone viral online. The images depict several stray dogs with bright blue fur, sparking comments that raise alarm and speculation that the animals had somehow mutated due to radiation exposure from the 1986 nuclear disaster.

Animal welfare group Dogs of Chernobyl, part of the Clean Futures Fund, confirmed that several blue-coloured stray dogs were indeed sighted within the exclusion zone in early October 2025. The group, which monitors and cares for the hundreds of stray dogs descended from pets abandoned after the 1986 disaster, noted that the animals appeared “active and healthy.”

While the dogs’ fur was unmistakably blue, experts quickly dismissed the idea that radiation was responsible. “There is no indication of mutation or illness,” one member of the welfare team told reporters, emphasising that the colour appeared to be external rather than genetic.

A more plausible explanation soon emerged: the dogs may have come into contact with chemical substances near abandoned industrial or sanitation facilities. IFLScience reported that one of the sightings occurred close to an old portable toilet containing bright blue deodorising fluid, which could easily stain an animal’s coat.

Still, there are competing accounts. The state-run Chernobyl monitoring authority told Swiss outlet Bluewin that the dogs were not contaminated but had been marked blue after sterilisation — a practice used to indicate that an animal has been neutered. Yet field workers from Dogs of Chernobyl dispute this, noting that standard sterilisation markings are small patches of colour applied to the head or ear, not the full-body coating seen in the viral footage.

Complicating matters further, some online commentators have questioned whether the footage itself is authentic, suggesting it could be AI-generated or digitally enhanced. However, the original video was posted by legitimate accounts linked to animal welfare operations in the area.

At this point, while the blue-coated dogs are real, the cause of their unusual appearance remains unconfirmed. All available evidence points to a chemical or environmental source, not radiation. No genetic tests or fur samples have yet been analysed, though the Dogs of Chernobyl team has expressed plans to capture the animals for study.