Fukushima Dogs Had Symptoms Comparable To Post-traumatic Stress Disorder

A new study published in Scientific Reports, now reveals, for the first time, the extent of suffering endured by those Fukushima dogs. Researchers at Azabu University in Japan compared the behavior of dogs rescued from disaster-hit Fukushima to dogs from the non-affected Kanagawa district. They showed that dogs rescued from Fukushima were seemingly repressed. They were less aggressive toward unfamiliar people and dogs, were more difficult to train and showed less attachment to people.

The Fukushima dogs' low trainability and attachment scores, as measured by six students who devoted at least 3 hours a day to a specific dog, are behaviors which also appear in people with post-traumatic stress disorder (PTSD). In those people, there is an oversecretion of such hormones like the stress-linked cortisol which impairs their ability to bond and get attached to others.

To investigate whether similar hormonal changes occurred in the Fukushima dogs, the researchers also monitored the dogs' urine cortisol levels. While they expected higher than normal levels, the 5-10 fold difference in cortisol levels observed in the Fukushima dogs compared to the Kanagawa ones showed that the dogs were very deeply stressed out. And yet, the high stress levels did not manifest as more aggressive behavior as is typically the case with dogs. This, inadvertently, may well mean that the stress made the Fukushima dogs more repressed instead.

After ten weeks of care and monitoring, the Fukushima dogs did get in better shape although they were still more stressed out than their Kanagawa counterparts. Their urine cortisol levels, for instance, were still more pronounced although to a lesser extent. They also became seemingly less repressed as they got less anxious and more attached with people, although they were still not as forthcoming as the Kanagawa dogs.

The researchers do point out that the behavioral changes and urine level of cortisol differences observed cannot be explicitly explained by the Fukushima disaster. The dog sample sizes were relatively low and as such other potential factors such as age of the dogs, for instance, cannot be disregarded. Regardless, the study does show that there was a deep tension in dogs which survived the Fukushima disaster without their families.

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Reference: Nagasawa, M., Mogi, K. & Kikusui, T. (2012) Continued Distress among Abandoned Dogs in Fukushima. Scientific Reports. DOI: 10.1038/srep00724.

Image credit: Selena Hoy (from flickr).