Equine insect bite hypersensitivity (IBH), also known as Sweet Itch, is an allergic skin disease in horses which presents as extreme itching and in turn damages the skin. Good skin health is important for the horse as the skin has several vital roles, including acting as a barrier to external challenges, helping to control body temperature, and also helping to make Vitamin D.
Pony suffering badly from Sweet Itch
What is Sweet Itch?
Sweet Itch is a skin allergy caused by a reaction to the saliva of the Culicoides species of midges. Horses with this condition typically suffer with severe itching from about March to October in the UK, when midges are active.
The irritation can cause the horse to rub and scratch the affected areas intensely, which can lead to patchy hair loss, sores and scabs. The mane and top third of the tail are the most common areas affected (Björnsdóttir et al., 2006). The abdomen, head, side of the body, and chest can also be affected, although to a lesser extent.
Hypersensitivity to the midge can be categorised into two allergies posing different reactions. Some horses may react immediately and often present in hives, whereas others (more commonly) have a delayed reaction causing itching to particular areas of the body, however some horses may have symptoms of both.
A vet will diagnose the condition following an examination which includes dermatologic testing. A of yet, cure has not been found despite ongoing research, however there are treatments for severe cases which include topical corticosteroids and systemic antihistamines.
How to manage your horse's Sweet Itch
- If you know your horse has previously suffered with sweet itch, it is important to start taking precautions early in the season.
- Avoid turning out between dawn and dusk when midges are most active.
- If possible, turn your horses out away from water source. Midges typically like to breed in a damp environment, so they are often more common by ponds and streams.
- Midges thrive on droppings. Therefore, poo-picking your horse’s fields should be a regular practice.
- Many owners of sweet-itch sufferers use a Boett ‘sweet-itch rug’. These rugs (pictured below) are designed with a fine mesh to prevent the midge from coming into direct contact with the horse, effectively acting as a barrier. Fly rugs will also help if you do not have access to a Boett rug.
- Fly repellents sprayed over the horse, particularly in sensitive areas such as the chest and the flanks can be useful in deterring midges from biting.
- Skin supplements can be very beneficial, particularly if they contain a high level of Omega-3 fatty acids, such as Feedmark’s EquiDermis.
If you suspect your horse is suffering with sweet itch or irritated skin, please seek veterinary advice on how best to treat the condition.
Example of a Boett rug
Nutritional support for your horse
Soothing the itching to keep your horse as comfortable as possible is very beneficial. This can be achieved through nutritional supplementation providing support from the inside out to optimise skin health.
Dietary supplementation with essential fatty acids (EFAs) may be useful in equine allergic conditions. Essential fatty acids are known to be crucial in maintaining skin barrier function and have a recognised role in inflammatory processes. Furthermore, Omega-3 fatty acids are especially renowned for their anti-inflammatory properties (Hess & Ross-Jones, 2014). Supplements high in Omega-3 fatty acids are those such as linseed oil, algae oil, and fish oils. Linseed oil is high in alpha-linolenic acid making it a suitable aid to support healthy skin tissue. Research has proven that when supplemented with linseed, horses showed significantly smaller skin test reactions to serum from the Culicoides midges. A reduction in the long-chain saturated fatty acids in analysed hair was also noted, which indicates changes in secretions from the skin and therefore a change in the ability to metabolize compounds involved in immune function. This evidence suggests a reduction in the overall immune response to the Culicoides midges.
Vitamin E is recognised as a powerful antioxidant, with human research indicating that it is regularly secreted on the facial skin surface, as this area is most exposed to environmental damage, and that it may play a pivotal role in the removal of free radicals from the skin, reducing cell damage and potentially benefiting skin health (Thiele et al., 1999, Williams & Carlucci, 2006). Vitamin E is also recognised for its immune-supporting actions (Bendich, 1993). A study conducted by Petersson et al. (2010) found that Vitamin E supplementation of predominantly older horses enhanced their general cell-mediated immunity (immune response driven by T cells, cytokines, and macrophages) and humoral immune functions (immune response mediated by antibodies). Vitamin E supplementation may therefore be particularly beneficial for horses suffering from sweet itch to aid their overall immune system.
Herbal nutritional options to optimise skin health from the inside out are also available. There are many herbs such as Marigold flowers, Brewer’s Yeast, Burdock root, Nettle, Clivers and Chamomile that can help soothe sensitive or irritated areas.
How can EquiDermis™ help to support your horse with Sweet Itch
EquiDermis contains the ingredients that have all been shown to be beneficial for skin health. For example, micronized linseed and linseed oil provide a high rate of natural omega-3 fatty acids which has been shown to control the immune response in sweet itch horses.
EquiDermis™ results after one month on horse that suffers from Sweet Itch
EquiDermis™ includes effective herbs including burdock root, chamomile flowers, clivers and nettle leaves:
- Burdock root has traditionally been used as a ‘tissue cleanser’ helps improve skin conditions.
- Chamomile flowers have been used to treat ailments of the skin for many years as it has shown to have antipruritic effects. Studies have shown that when animal diets are supplemented with chamomile, scratching behaviour is reduced.
- Clivers (or cleavers) has often been used as a remedy for dry skin and is believed to be particularly effective when combined with burdock.
- Nettle leaves are commonly fed to horses affected by sweet itch as it is thought they help to clean the blood and offer support to the liver and kidneys, which work efficiently to eliminate toxins from the body.
Brewer’s yeast has also been added as it is a natural source of B vitamins and amino acids which help to support optimum skin health.
Reviews
To read more of our fantastic reviews please click here. If you would like any further advice please don't hesitate to contact our registered Nutritionist Steph on 0800 585525 or email [email protected].