The Mystery of Seasonal Canine Illness

An investigation by Phoebe Foo 

Seasonal Canine Illness (SCI) was first identified in 2009 in dogs who had recently visited woodland areas of The Queen’s Sandringham Estate in Norfolk, England. Around the same time some dogs walking in Thetford (Norfolk/Suffolk), Sherwood (Nottinghamshire) and Rendelsham (Suffolk) Forests and also the Clumber Park estate in Nottinghamshire showed signs of illness consistent with the symptoms of SCI. The occurrences of SCI seem to be mainly confined to the east of England and East Anglia.


So, what exactly is Seasonal Canine Illness? The cause of this disease is so far unconfirmed, it has been thought in previous year that the cause was somehow linked to natural toxins found in woodland algae and fungus, but this has now been discounted. Agricultural toxins were also considered and similarly disregarded. Currently the presence of British harvest mites in woodland environments is being considered. SCI occurs between August and November (with its peak in September), which is just the time of year when harvest mite larvae are prevalent. The harvest mite connection is still being investigated but it is being seriously considered as a possible cause by a growing number of researchers.

SCI has several symptoms, many of which sadly are vague and can easily be attributed to several other disorders and illnesses. Symptoms are as follows:

*  Upset stomach

*  Vomiting and diarrhoea

*  Abdominal tenderness

*  Loss of Appetite

*  High Temperature

*  Tremors

Sometimes a rash is also present; this will be most visible on the abdomen


In affected dogs symptoms will show between 24 and 72 hours of a woodland walk. If your dog presents with any of these symptoms contact your vet immediately. SCI can progress quickly and rapid action is important. There is currently no test for SCI and your vet may need to make a judgement call. Advise your vet that your dog has walked in woodland 24 to 72 hours previously and ask him to check for harvest mites. They are tiny reddish brown creatures which can be seen on close inspection around the dog’s ears and on the paws. 

Prompt treatment is important as SCI can result in fatality if not dealt with quickly and appropriately. Diagnosis can be challenging, but more and more veterinarians are aware of it and can act quickly. Treatment with IV fluids and anti sickness medication may be used and also your vet may advise treatment with a Fipronil spray if mites are present. If treated promptly, most dogs will recover in 7 to 10 days. Sadly this disease can be fatal, though fatalities seem to be dropping as awareness spreads. In 2010 20% of cases resulted in fatality, by 2012 this had reduced to 2%. 


I am sure you are by now wondering how you can prevent an encounter with SCI. As SCI is still somewhat of a mystery, the advice is vague and varies depending on where you look. The Animal Health Trust recommends asking your vet for a Fipronil spray to apply immediately before walks. Spray application is preferred to spot on treatments as coverage can be better controlled. Fipronil is a prescription only product which is used against fleas and ticks, but is also effective against harvest mites and can only be obtained from your vet. You may also want to avoid woodland, especially woodlands known to be affected by SCI in autumn and winter. The Woodland Trust cautions that ‘long car journeys prior to and after walking in these areas may also be a risk so taking plenty of breaks during the journey and always having access to water may also help’. There is also a possibility that small breeds may be more susceptible to SCI, though this cannot be confirmed.


Phoebe Foo

Northern Editor UK

31st August 2017

Print Print | Sitemap
© Diana Bailey