Summer Health Issues: Sweet Itch with NAF

Kate Hore RNutr (Animal) R.Anim.Technol. Head Nutritionist at NAF

Summer is here, and with that the longer days, better weather and more opportunities to ride. But it’s not all good news for some of our equines. Just as we may be prone to summer associated health issues, such as hayfever, so some horses and ponies are susceptible to allergies and intolerances through the nicer weather, with one of the most common being Sweet Itch.

What is Sweet Itch?

Sweet Itch, also known as Summer Seasonal Recurrent Dermatits (SSRD) is an allergic reaction to the bit of the Cullicoides midge. Signs will be seen as intense itching, particularly along the mane and top of the tail, though we also frequently see head and belly rubbing. Hair loss and sore, inflamed areas of skin may be seen, as will raised, ridged skin if the condition worsens. Needless to say, affected horses and ponies will also be particularly irritated by flying insects, and especially those pesky midges!

Researchers have found evidence of a genetic link with Sweet Itch, which may explain why we see some breeds, including Shetlands, Shires, Welsh and Hackneys, all recognised as more likely to suffer. Equally, research shows the importance of early exposure to the allergen to initiate the individual’s natural defence. Hence we see a high level of Sweet Itch in exported Icelandic horses, as the absence of the Cullicoides midge in their native Iceland means they don’t have early life exposure to the allergen.

Managing a horse with Sweet Itch

The correct management can be really useful to help those suffering from Sweet Itch. By taking some simple management and dietary steps we can hopefully help all of our horses and ponies to enjoy the long summer days as much as we do.

  • Consider stabling during peak times of day, particularly early morning and early evening, when both midges and general flying insects can be at the worst.
  • When they are turned out, for Sweet Itch horses and ponies, try to choose an open aspect field, preferably on a hill which encourages a constant light breeze.
  • Avoiding turnout in fields with standing ponds or any water sources where flies congregate is a must.
  • Fly rugs may prove useful
  • Don’t forget regular use of a strong, proven fly repellent. It is worth remembering that, legally, all fly repellents are registered for safety and efficacy. Therefore, to ensure you’re using an approved product, check the label for the HSE or BPR registration number.

While external approaches are important, it is fair to say that skin health comes from within, and targeted nutrition is advised. Natural antioxidants can support the body’s own defence systems, while key nutrients such as MSM (Methyl sulphonyl methane) is an important sulphur donor, an intrinsic part of maintaining strong, healthy skin and coat.


Björnsdóttir S, Sigvaldadóttir J, Broström H, Langvad B, Sigurdsson A. Summer eczema in exported Icelandic horses: influence of environmental and genetic factors. Acta Vet Scand. 2006 May 26;48(1)

Citek J, et al. Genetic parameters of insect bite hypersensitivity in the Old Grey Kladruber horse. J Anim Sci. 2017 Jan;95(1):53-58.

Wilson AD, Harwood LJ, Björnsdottir S, Marti E, Day MJ. Detection of IgG and IgE serum antibodies to Culicoides salivary gland antigens in horses with insect dermal hypersensitivity (sweet itch). Equine Vet J. 2001 Nov;33(7):707-13.

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