What is Post Traumatic Stress Disorder in Dogs? Why Dr. Miho Nagasawa’s research paper about ABANDONED DOGS AT FUKUSHIMA, JAPAN and PTSD-LIKE EFFECTS IN DOGS is so important.

Why Dr. Miho Nagasawa’s research paper about ABANDONED DOGS AT FUKUSHIMA, JAPAN and PTSD-LIKE EFFECTS IN DOGS IS SO IMPORTANT.Impaired learning and an inability to bond with humans were two of the post- traumatic disorder symptoms displayed by both humans and dogs.Cortisol levels in the Fukushima dogs remained at higher levels than the Kanagawa dogs, even after ten weeks of care.

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Image Credit: Claudia Bensimoun

In order to recognize the signs of stress in performance or working dogs, one must try to visualize the external stressors in a dog’s environment. Although it is impossible to measure levels of stress, it is certainly possible to measure certain stressors in a dog’s environment.

Understanding some of these signs of stress in working dogs that may include:

Panting, yawning, avoiding eye contact, shivering, licking, tucked tail, general restlessness, muscle tension, zooming around the ring and avoidance of the handler or pet parents is key to improving overall performance in dogs.

While many handlers and dog parents are familiar with some of these stressful behaviors, it may be interesting to note that many of these behaviors were found in the Fukushima dogs in Japan.They can also be found in rescue dogs that have had traumatic experiences in the past.

In agility dogs where speed, accuracy and timing are important, many performance/working dogs may display signs of stress when in a new environment.

According to Dr. Miho Nagasawa’s research paper, the dogs that were abandoned at Fukushima, Japan displayed severe symptoms of canine stress, similar to humans with post-traumatic stress disorder. Although this varies from the stress experienced in performance dogs, stress and its effects on learning and behavior in all canines should not be ignored.

A dog’s well-being depends on the absence of stress. Although some research papers say that a little bit of stress may be beneficial to a dog’s performance.

According to Dr. Miho Nagasawa the Fukushima dogs had stress hormones that were far higher than normal and that lasted over a period of ten weeks.

“ The Fukushima dogs had significantly less aggression toward unfamiliar people, were harder to train, and exhibited less attachment to caregivers than the dogs from the other region of Japan.” Miho Nagasawa, Veterinary scientist and author via Los Angeles Times, Science Now.

“In Fukushima, Japan, a prolonged refugee situation caused by a major nuclear incident after the earthquake of March 11, 2011 has led to the unintentional abandonment of many pets. We received stray or abandoned dogs from rescue centers in Fukushima Prefecture. During re-socialization training and health care, we accessed the behavioral characteristics and the urine cortisol level of each dog and compared them with those of other abandoned dogs not involved in this earthquake. The dogs from Fukushima showed significantly lower aggression toward unfamiliar people, trainability, and attachment to their caretakers; also, urine cortisol levels in the dogs from Fukushima were 5–10-fold higher than those in abandoned dogs from another area of Japan. These results suggested that the dogs from Fukushima suffered through an extremely stressful crisis.”   Miho Nagasawa via Nature’s Scientific Report.

“In human studies, chronic stress has been shown to induce psychological disorders. We expected that the Fukushima dogs might be under chronic stress and show behavioral and neuroendocrine stress responses that may possibly be attributable to the above-mentioned unusual living environments. Therefore, in order to elucidate the impacts of stress from one of the highest magnitude earthquakes recorded in history, we compared behavior and urinary cortisol levels between disaster-affected dogs and non-disaster-affected abandoned dogs. The levels were significantly higher in dogs from Fukushima than in those from Kanagawa. Fukushima dogs’ urinary cortisol levels were highest on the day of arrival and declined significantly after the 8th day, while the Kanagawa dogs showed no significant changes in urine cortisol levels over time.Humans affected by the disaster are already recovering and gradually returning to normal life. However, our results suggest the possibility that stress can induce excessive, deep psychosomatic impacts with implicit behavioral manifestations, such as deficits in attachment and learning ability also in dogs. Long-term care and concern regarding the psychological impact of disasters appears necessary in humans and companion animals.” Miho Nagasawa and colleagues via Nature’s Scientific Report.

Dogs that experience stressful or traumatic events can carry psychological trauma. Walk through any dog shelter in Japan and one will experience the most common behavioral problems associated with post- traumatic stress disorder. (PTSD). Shaking, cowering, shying away from people and excessive barking are among the few behavioral changes that these dogs may experience. Dogs like people can feel stressed confused and unloved.

Dogs that were left stranded in the Fukushima exclusion zone after the nuclear crisis have had to survive many of the devastating affects: High radiation levels, lack of food, freezing temperatures and sudden changes in their environment and family.

Canines and humans display similar symptoms after life changing events. Veterinarians will go as far as prescribing anti-anxiety medications or anti-depressants. This combined with the work of an understanding trainer is found to help dogs desensitize from situations that they find stressful.

The numerous meltdowns at the Fukushima Daiichi Nuclear Power Plant in March 2011, not only caused a humanitarian crisis, but created a crisis for all pets as well. More than 100,000 people had to be evacuated from within the 20-kilometer radius.

Dogs were left feeling traumatized. Today researchers have evidence that the Fukushima event was so devastating for the 5800 dogs that were registered in the area, that when tested, these abandoned dogs had extremely high levels of cortisol, a stress hormone in their urine. Researchers compared behavior patterns and levels of cortisol in dogs that had been rescued and found evidence that dogs do indeed suffer from post- traumatic stress disorder. (PTSD)

Yuki was discovered wondering alone in the Fukushima exclusion zone. The ghost -like town that surrounds the quake-crippled nuclear reactor is the home to many abandoned dogs that were either left chained or wandering alone. Haggard and stressed, Yuki seemed to be suffering from a canine form of post-traumatic stress disorder. In a paper published in Scientific Reports 2012, Miho Nagasawa, a veterinary scientist and author, stated that abandoned and stray dogs that were recovered in the Fukushima area, also suffered from the lingering effects of the earthquake.

According to the report the Fukushima strays also showed difficulty with learning and developing an attachment to humans. Nagasawa studies animal cognition and endocrine response and admits that although the study involved only a small number of dogs: 17 , the devastating effects of extreme stress in these dogs were very similar to the symptoms of post-traumatic stress disorder in people.

Researchers concluded that all the abandoned Fukushima dogs that had received specialized veterinary care and re-socialization training, did not overcome the severe effects of extreme stress.

“The dogs from Fukushima showed significantly lower aggression toward unfamiliar people, trainability and attachment to their caretakers; also, urine cortisol levels in the dogs from Fukushima were 5-10 fold higher than those in abandoned dogs from another area of Japan.” Miho Nagasawa explains via Los Angeles Times, Science Now.

Although the study involved only a small number of dogs-17 dogs from the Fukushima exclusion zone, these dogs along with another group of dogs from Kanagawa, Japan, were taken to a special dog rescue program at Abazu University. Both groups of dogs were then given veterinary care and trained; so that they could be re-home later on. Nonetheless, Miho Nagasawa and colleagues stated that the cortisol levels in the Fukushima dogs remained at higher levels than the Kanagawa dogs, even after ten weeks of care.

Impaired learning and an inability to bond with humans were two of the post- traumatic disorder symptoms displayed by both humans and dogs.

Miho Nagasawa and his colleagues, says it is unclear whether the greater stress in the Fukushima dogs resulted from experiencing the devastating 9.0-magnitude earthquake in 2011, the unusual and sudden disappearance of humans or the length of time it took to rescue all the abandoned dogs in Fukushima.

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Woofs & Wags!


Copyright © 2016 Claudia Bensimoun






  1. http://www.pbs.org/newshour/rundown/2011/11/the-collie-in-the-coal-mine-whats-to-come-of-the-fukushima-dogs.
  2. http://www.theepochtimes.com/n2/science/after-fukushima-dogs-suffer- ptsd-like-symptoms-302900.html
  3. http://news.sciencemag.org/sciencenow/2012/10/scienceshot-fukushima-             dogs-were-.html Scientific Reports 2, Article number: 74
  4. http://www.nature.com/scitable/blog/labcoat-        life/fukushima_dogs_had_symptoms_comparable
  5. http://www.nature.com/srep/2012/121011/srep00724/full/srep00724.html









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