September 2012 Update on Mysterious illness Killing Dogs

Last September, The Disease Daily wrote of a mysterious illness killing dogs who had walked in wooded areas in the East of England Region. The illness, called Seasonal Canine Illness (SCI), was first reported in 2009 and cases have continued to be reported each autumn. A recent warning was issued to dog owners as the fall season approaches in the United Kingdom, and as a cluster of possible cases was discovered in Thetford, England. Another possible case is being investigated in Nottinghamshire.

An investigation into SCI was launched in 2010 by the Animal Health Trust (AHT) that initially focused on four study areas: Sandringham Estate and Thetford Forest in Norfolk, and Sherwood Forest and Clumber Park in Nottinghamshire. A fifth site, Rendlesham Forest in Suffolk, was added in 2011. As part of this investigation, the AHT has asked dog owners who have walked their dogs in any of the above areas (even if their dog did not become ill) to complete an online questionnaire. Investigators hope to obtain information on the activities and behaviors of dogs during visits to the study areas to assess potential exposures. To date, over 600 questionnaires have been completed. Of the 600 questionnaires, 157 reported illness in a dog and 15 reported death of a dog. It should also be noted that while the investigation focuses on the above five sites, dogs walked in any woodland area in autumn could be at risk of SCI.

In addition to the questionnaire, the AHT, in collaboration with the Natural History Museum and the Institute of Zoology in London, has conducted multiple site visits to investigate the possibility that a naturally reoccurring toxin, perhaps from a plant or fungi, could be the cause of SCI. Results of site visits have so far yielded no significant findings regarding environmental toxins. Other possible causes are being investigated. One theory is that the illness may be associated with harvest mites or bird species such as wood pigeons.

Clinical signs of SCI include vomiting, diarrhea, abdominal pain, lethargy, loss of appetite, shaking, and fever. Most report onset of symptoms within 24-72 hours of having visited a woodland area. The illness has not been shown to be able to be passed between dogs, however a contagious pathogen has not been ruled out.