In particular, I want to speak about Sweet Itch. Sweet Itch is an allergic reaction by horses to the saliva of the biting midge Culicoides. Previously prevalent in ponies in the northern hemisphere, Sweet Itch is becoming more and more widespread.
This is what Sweet itch looks like.
Culicoides is a blood-sucking midge found in wet, marshy areas or in dew or raindrops during the summer months. (It is also the insect that transmits AHS.) Once the horse is bitten, small intensely itchy lumps sometimes appear on the skin, usually along the horse’s back, belly, mane and tail. Because they are so itchy, the horse will often develop secondary skin eruptions and infections after vigorously rubbing or biting the itchy lumps.
Why would my horse react to the bite, while other horses have no reaction?
Your horse’s immune system is the army that is there to fight off infection. Which is very useful if he gets sick or cuts himself or something. The immune system works by first recognising the ‘intruder’ (aka the antigen, in scientific terms) as being foreign and dangerous. Then, it sends out soldiers to fight off the infection. One of the ‘soldiers’ sent out is called Immunoglobulin E (IgE). IgE causes mast cells to release histamine, which causes swelling, itchiness, discharge or wheezing.
In an allergy, your horse’s immune system acts like an over-protective army (to continue the army analogy). This army over-reacts by sending out huge amounts of histamine even when the ‘intruder’ is harmless – a dust mite or the Culicoides bite or a component of food. Which results in the out of control itching, familiar to Sweet itch sufferers.
What can I do, naturally, to help?
If your horse has Sweet Itch, or even if he or she has had it previously, try this:
- Keep the horse stabled during dawn, dusk and hot, humid days
- Use an effective fly repellent
- Give a natural remedy which modulates the immune system – I suggest Immune mix from The Herbal Horse.
- Apple Cider Vinegar can be given internally (30 ml per day) as well as used as a rinse externally (2 tablespoons in a litre of water). Do not use the rinse if the lesions are rubbed open, as the vinegar will sting.
- On open lesions, apply an ointment containing calendula or propolis.
- A homeopathic remedy called Culicoides midge, made from the midge itself be helpful. Consult a homeopath to prescribe this.