Sweet Itch, or Summer Seasonal Recurrent Dermatitis (SSRD), is a problem that affects thousands of horses, ponies and donkeys in many countries of the world to a greater or lesser degree. Virtually all breeds and types of ponies and breeds can be affected, from tiny Shetland ponies to heavyweight draught horses, although the condition is rare in English Thoroughbreds. In South Australia reports say that as many as 60% of horses and ponies are affected. About 5% of the UK horse population are thought to suffer. Although known by different names (e.g. Sommer Ekzem in Germany, Kasen in Japan, Queensland Itch in Australia), the symptoms are the same.
Symptoms include severe pruritus [itching], hair loss, skin thickening and flaky dandruff. Exudative dermatitis [weeping sores, sometimes with a yellow crust of dried serum] may occur. Without attention sores can suffer secondary infection.
The top of the tail and the mane are most commonly affected. The neck, withers, hips, ears and forehead, and in more severe cases, the mid-line of the belly, the saddle area, the sides of the head, the sheath or udder and the legs may also suffer.
The animal may swish its tail vigorously, roll frequently and attempt to scratch on anything within reach. It may pace endlessly and seek excessive mutual grooming from field companions. When kept behind electric fencing with nothing on which to rub, sufferers may scratch out their mane with their hind feet and bite vigorously at their own tail, flanks and heels. They may drag themselves along the ground to scratch their belly or sit like a dog and propel themselves round to scratch the top of their tail on the ground.
There can be a marked change in temperament – lethargy with frequent yawning and general lack of ‘sparkle’ may occur, or the horse may become agitated, impatient and, when ridden, lack concentration. When flying insects are around he may become agitated, with repeated head shaking.
Diagnosis is not usually difficult – the symptoms and its seasonal nature (spring, summer and autumn) are strong indicators. However symptoms can persist well into the winter months, with severely affected cases barely having cleared up before the onslaught starts again the following spring.
Horses that go on to develop Sweet Itch usually show signs of the disease between the ages of one and five and it is common for the symptoms to appear first in the autumn.
There is anecdotal evidence that stress (e.g moving to a new home, sickness, or severe injury) can be a factor when mature animals develop Sweet Itch.
Hereditary predisposition may bea factor in Sweet Itch and work to identify the gene(s) responsible is at an early stage. However environmental factors play a major part – where the horse is born and where it lives as an adult are at least as significant as the bloodlines of its sire and dam.
Sweet Itch is not contagious, although if conditions are particularly favourable to a high Culicoides midge population, more than one horse in the field may show symptoms.
In the UK Sweet Itch is classified as an unsoundness and, as such, should be declared when a horse is sold.
The disease is a delayed hypersensitivity to insect bites and results from an over-vigorous response by the animal’s immune system. In the process of repelling invading insect saliva (which actually contains harmless protein) the horse attacks some of its own skin cells ‘by mistake’ and the resulting cell damage causes the symptoms described as Sweet Itch.
In the UK several species (of the 1,000 or so that exist) of the Culicoides midge and, to a lesser extent, the larger, hump-backed Simulium Equinum, a member of the blackfly family, are responsible. Each has a preferred feeding site; Culicoides tend to be body feeders and the Simulium earfeeders.
Culicoides adults mainly rest among herbage and are most active in twilight, calm conditions. Breeding sites are commonly in wet soil or moist, decaying vegetation. They are tiny, with a wing length less than 2 mm and able to fly only a short distance (100 metres or so).
Male Culicoides are nectar feeders, but soon after hatching the females mate and require a blood meal to mature their eggs. They do not fly in strong wind, heavy rain or bright, clear sunshine. They dislike hot, dry conditions. The grey light at dusk and dawn suits them well, and they are at their most active at these times. However, as they are poor fliers, if there is too strong a wind, or rain during early morning they will simply wait until later to feed. Likewise they may feed at any time during humid days with cloud cover.
Culicoides are on the wing and breeding from as early as late March until the end of October, depending on geographical location. There is only a short breeding season each year in the north of Scotland, while in the south of England larvae will hatch throughout the spring, summer and autumn, depending on weather conditions. Seasonal variations in the weather can have an impact – recent winters have been milder and damper allowing breeding to start earlier. Summers that are alternately sunny and rainy cause an increase in midge breeding habitats and therefore an increase in the numbers of midges that are around to bite. Under these conditions most horses will show symptoms of Sweet Itch to some degree. Culicoides numbers are the critical factor.
Culicoides larvae are able to survive severe frosts but they do not survive prolonged drought conditions.
Research into how Culicoides locate their prey indicates that they primarily do so by sight.
At present there is no cure for Sweet Itch. Once an animal develops the allergy it generally faces a ‘life-sentence’ and every spring, summer and autumn are a distressing period for horse and owner alike. The animal’s comfort and well being are down to its owner’s management.
There are two basic approaches:
MINIMISE MIDGE ATTACK
Ensure pasture is well drained and away from rotting vegetation (e.g. muck heaps, old hay-feeding areas, rotting leaves).
Stable at dusk and dawn, when midge feeding is at its peak, and close stable doors and windows (midges can enter stables). The installation of a large ceiling-mounted fan can help to create less favourable conditions for the midge.
For slight to moderate cases of Sweet Itch this can help. However a seriously itchy, stabled horse has hours of boredom during which to think up new ways of relieving his itch – manes and tails can be demolished in a few hours of scratching against a stable wall. If stabling can be avoided it is best to do so.
· Use an insect repellent. Some are effective against flies but their effectiveness against Culicoides is unproven.
DEET (the acronym for N,N-Diethyl-m-toluamide), has a track record stretching back over 40 years and has proven to be highly effective. It is the active ingredient in many midge and mosquito repellents for use by people. Research has shown that the higher the concentration of DEET in a repellent the more effective and long-lasting it is likely to be. (See ‘Spray Gold DEET)
Use an insecticide.
Some owners achieve good results with insecticides whilst others find they have shown little benefit in controlling Sweet Itch.
Benzyl benzoate was originally used to treat itch-mites (scabies) in humans and has been used for many years to combat Sweet Itch. In its neat form it is a transparent liquid with an aromatic smell, but it is more commonly obtained from Vets or pharmacies as a diluted milky-white suspension. It is listed as an ingredient in several proprietary formulations, including Carr, Day & Martins’ ‘Kill Itch’ and Pettifer’s ‘Sweet Itch Plus’.
Benzyl benzoate should be thoroughly worked into the skin in the susceptible areas every day. However it is a skin irritant and should not be used on the horse if hair loss and broken skin have occurred – application should therefore start before symptoms develop in the spring. If used later its irritant properties can cause areas of skin to slough-off, in the form of large flakes of dandruff.
Other insecticides, including permethrin and related compounds, tend to be longer lasting but should also be used with care. Permethrin is available by veterinary prescription (e.g. Day, Son & Hewitt ‘Switch’ pour-on liquid). Application instructions should be followed.
Note: Gloves should be worn when applying insecticides, including benzyl benzoate. Particular care should be taken if they are used on ponies handled by children – they can cause eye irritation, for example if fingers transfer the chemical from the pony’s mane to the eyes.
Coat the susceptible areas of the horse with an oil . Midges dislike contact with a film of oil and they will tend to avoid it. Commonly used preparations include Medicinal Liquid Paraffin, and ‘Avon Skin-so-Soft’ bath oil (diluted with water). There are several oil-based proprietary formulations, for example Day Son & Hewitt’s ‘Sweet Itch Lotion’.
Oils and other repellents that are effective usually work for a limited time: In summer a horse’s short coat-hair does not retain the active ingredient for long and it can be easily lost through sweating or rain. Re-application two or three times every day may be necessary.
Greases (usually based on mineral oils) stay on the coat longer, but they are messy and therefore not ideal if the horse is to be ridden. They can be effective if only a small area of the horse is to be covered. However it is impractical and often expensive to cover larger areas.
Some preparations contain substances (e.g. eucalyptus oil, citronella oil, tea tree oil, mineral oil or chemical repellents) that can cause an allergic skin reaction. Always patch test first on the neck or flank of the horse – apply to an area about 3 cm across and look for any sign of swelling or heat over a 24 hour period before using more extensively.
Use a Boett® veterinary blanket. This is by far the most effective Sweet Itch protection to date and avoids the need need to use insecticides, oils or greases.
ALLOW MIDGE ATTACK, BUT TRY TO MINIMIZE THE RESULTANT ALLERGIC REACTION BY:
The use of anti-histamines may bring some relief but high dose rates are required and they can make the horse drowsy.
Applying soothing lotions to the irritated areas. Soothing creams such as Calamine Cream or ‘Sudocrem’ can bring relief and reduce inflammation, but they will not deter further midge attack. Steroid creams can reduce inflammation.
It is often difficult to assess the effectiveness of a particular treatment. The incidence and severity of Sweet Itch is so highly dependent on midge numbers, apparent success may simply reflect a temporary fall in numbers due to a change in the weather, for symptoms only to return again later when weather conditions are more midge-favourable.
The Boett (pronounced Bo-ett, as in Go-get!) Blanket was invented in Sweden 16 years ago to offer protection to horses and ponies suffering from insect-bite allergy. It has been continually developed since then and is now used around the World as the best way to manage Sweet Itch, whilst avoiding undesirable side effects.
Ideally the horse should start wearing the blanket before symptoms appear, but even later in the season, once the blanket is fitted, sores will quickly heal and mane and tail growth restart. Typically it will take from one to three weeks after the blanket is fitted for damaged skin cells to recover and itchiness to decline. Horses wearing the blanket all summer keep their full manes and tails and have glossy, clean coats and those susceptible to sun sensitivity and contact nettle rash are also helped.
The Boett is different from other designs of horse blanket and should fit snugly, apart from the neck where there is ample fabric to ensure full cover when the horse puts his head down to graze. It covers the neck, the body and the tail and consists of two separate pieces: The mane, neck, body and tail-piece is fitted over the head (it is extremely rare for a horse to object to this) and there is an elastic neck band which adjusts behind the ears for a snug fit. The separate adjustable belly-flap is attached over the blanket with two elastic surcingles and a chest strap. It takes only a couple of minutes to fit.
The Boett Blanket and Hood fabric is resilient. It is strong enough to withstand normal horse activities – rolling, mutual grooming, galloping etc. Horses being horses, it must however allow an animal to break free should it become hooked-up on anything. For this reason common sense should be applied to the use of the blanket if it is not to get torn. Electric fencing is ideal for horses with Sweet Itch, considerably prolonging the life of the blanket. Barbed wire is totally inappropriate and certain types of hedging or rough stone walls can also cause damage to a seriously itchy animal. If that animal just happens to be wearing a brand new blanket the outcome can be disastrous. The animal’s environment should therefore be checked for protruding nails, jagged branches on hedges or trees and other sharp objects that could cause damage.
Boett of Sweden are justifiably proud of their workmanship and quality control-blankets never ‘self destruct’ while the horse is grazing! If a blanket does suffer damage the reason is usually obvious- unsuitable field boundaries or even an aggressive herd leader’s teeth can be responsible. It makes sense to take steps to avoid these potential problems. Experience shows that, on average, a blanket will last for three years on mares and two years on geldings… . boys will be boys!
Horses at grass, including mares with foals at foot, can wear the blanket permanently to great benefit, 24 hours per day, every day, all summer long. Indeed, a significant number of horses even wear the blanket during mild spells in winter when midges can be on the wing.
Individuals that require stabling should continue to wear their blanket inside, unless the building is completely midge-free – very difficult to achieve. The Blanket can be worn under a rug in late autumn and early spring, though care should be taken to make sure over-heating doesn’t occur.
Horses and ponies realize very quickly that the blanket makes them more comfortable – as far as they are concerned the benefits are such that, other than when the blanket is in the washing machine, there is no good reason to remove it.
The Boett Hood
Two out of three horses with Sweet Itch suffer damage to the head area. The ears, forehead and around the eyes are commonly affected. For these animals the Boett Hood offers protection. It has ample adjustment and is secured to the blanket by a loop behind the ears, a long elastic strap, which is fastened to a point inside the blanket by the wither area and by two snap-clips below the cheeks. No head collar is required.
As with the blanket, horses rarely object to the fitting and use of the hood. It is available in six sizes.
Other items we recommend are:
The Midge Mask
Prevents damage around the eye and protects the face from forehead to muzzle. The mask also stops fly-borne ‘runny-eye’ infections and is suitable for all horses, ponies and donkeys. The mask can be worn alone or with the Boett Hood (unlike the Boett Hood, the midge mask does not protect the ears).
‘Spray Gold’ Deet (min 98%)
The most effective midge repellent known to man! Use on areas not covered by the Boett Blanket or if the blanket is removed for riding – spray or wipe-on. A summer «must» for all equines- and riders too. ‘Spray Gold’ Deet is available as a 200ml mist spray and a 500ml Refill.
‘Pure Gold’ Ointment
The Boett Blanket does a wonderful job on the areas that it covers. However some horses and ponies are also bitten on the sheath and on the legs. These areas are impossible to cover with fabric – this is where ‘Pure Gold’ comes into its own, forming a protective barrier between the midge’s mouth and the animal’s skin.
‘Pure Gold’ is a refined, long-lasting, thick ointment that will not melt or run off in hot weather. It is kind to both horse and human skin. We don’t make any claims for healing properties (our own horses respond best to ‘Sudocrem’ antiseptic cream where healing is required) but we do find it deters further midge attack.
‘Pure Gold’, which can be removed using our Non-Allergenic Shampoo, is available in 300g and 1200g tubs.
Regular shampooing can benefit the condition of allergic horses and ponies. Weather permitting, we also advise you to shampoo your horse before fitting the Boett Blanket – it doesn’t make sense to put a clean Blanket onto a dirty horse.
Many horses with Sweet Itch have very sensitive skin. From our own experience, and from speaking to others, we know that some shampoos containing for example, Tea Tree Oil, Citronella, Oil of Eucalyptus and other additives may cause dramatic allergic reactions. This concentrated-formula Non-Allergenic Shampoo is a powerful cleaning shampoo containing no added perfume or colour. It contains no cheapening additives such as salt and it is pH neutral – it is safe to use on even the most delicate areas as frequently as required. It is also a low-lather formulation, which makes thorough rinsing after shampooing easier and leaves the coat clean and shiny.
We have tested many different shampoo formulations and we are sure that for all allergic horses and ponies and those with sensitive skins this formulation is ideal. It is available in 500ml and 4 litre containers.
Whichever shampoo you use it is important to rinse your horse thoroughly afterwards. A low-lather shampoo makes this easier.
Q. Does the Boett Blanket really work?
Q. How does it work?
Q. How quickly will I see results?
Q. Should I apply repellent or insecticides under the blanket?
Q. Which midge repellent should I use when I take the blanket off to ride my horse?
Q. Is the Blanket waterproof?
Q. Will my horse over-heat in hot weather when he is wearing the blanket?
Q. When should my horse start/stop wearing his blanket?
Q. Should my horse wear the blanket in his stable?
Q. Can I place a rug on top of his Boett Blanket during spring and autumn?
Q. Can I keep the Blanket on when I ride my horse?
Q. I have a young horse that is expected to grow. Should I allow for this when ordering the blanket?
Q. Will midges crawl under the blanket?
Q. If my horse is bitten, for example on his head or legs, will the symptoms of Sweet Itch appear elsewhere on his body?
Important ordering information
The Boett Sweet Itch Blanket fits in a unique way. To enable us to supply you with the correct size we require exact information. Please therefore take the time to measure precisely, and to complete the form accurately. If you have one available, a fairly recent photograph of your horse or pony is helpful to us.
Measuring for a Boett Blanket:
Ordering a Hood
It is not possible to measure all the planes and angles of a horse’s head to produce useful measurements for sizing the hood. However it is helpful for us to know precisely which head collar or bridle size your horse wears (e.g. is it Small Cob, Medium Cob or Large Cob rather than just «Cob Size») – and similarly with pony and full size. Also please tell us if your horse or pony has a particularly small or large head in comparison to the rest of his build.
Placing Your Order
Deduct £21 from all Blanket prices listed here to celebrate Boett’s 21st Birthday.Product Price
Boett Hood: All sizes £52.64
Boett Top ‘n’ Tail £76.50
Mesh Midge Mask: All sizes £12.90
Shampoo 500ml £8.90
Note: Prices for the Midge Mask, Shampoo, Spray Gold & Pure Gold include VAT and p&p.
MYTH: Sweet Itch is a rare condition; REALITY: About 1 in 20 horses and ponies in the UK suffer.
MYTH: Spring is the worst time for Sweet Itch; REALITY: Autumn is often the worst time.
MYTH: Sweet Itch only affects pony breeds; REALITY: There are many horses of 15hh and over with sweet Itch.
MYTH: All midges cause Sweet Itch; REALITY: The dancing midges that appear over water and bushes are larger and are non-biting.
MYTH: Culicoides need streams and rivers to breed; REALITY: They breed in moist soil, rotting vegetation and muck heaps, not in flowing water.
MYTH: Culicoides need trees; REALITY: They can shelter in any herbage, including grass. But trees do create still air, which they prefer.
MYTH: Sweet Itch is due to eating rich, sweet grass in Spring – hence the name «Sweet Itch»; REALITY: It is coincidence that midges emerge to do their damage in the Spring.
MYTH: Some horses are bitten, others are not; REALITY: All horses may be bitten but only some individuals show an allergic reaction
MYTH: Horses can be protected from Sweet itch by feeding garlic; REALITY: Culicoides find their prey mainly by sight, not smell.
MYTH: Feed additives can help Sweet Itch; REALITY: We have had no success with mineral supplementation and it is difficult to see how it could impact on an immune system disorder. Claims are also made for substances which «can be fed to horses with Sweet Itch». We know of no reliable reports of equine clinical trials that support these claims. Indeed one could say «Polo Mints can be fed to horses with «Sweet Itch»
MYTH: Boosting the horse’s immune system will help Sweet Itch; REALITY: Sweet Itch is caused by an over-active immune system, not one that needs boosting!