Sweet Itch is one of the most common skin diseases seen in the horse. About 2.8% of horses in the UK are affected to some degree. Most horses first start showing signs when they are between 1 and 4 years of age and the condition generally worsens with each summer. All too often ponies purchased during the winter months prove to have Sweet Itch the following summer!
Certain breeds are particularly prone to the disease; Icelandic horses, Friesians, Shetland ponies, Shires, Hackneys and Welsh ponies have all been suggested as susceptible breeds.
Sweet Itch is caused by hypersensitivity to the bite of the tiny Culicoides midge. There are approximately 20 species of Culicoides present in the UK. The fly is active from March to October but peaks in numbers in May to September. Culicoides are very small and can pass through conventional mosquito netting. They are most active during dawn and dusk. The midges breed in aquatic habitats; any standing water, decaying vegetation and even manure is sufficient.
The worst affected sites are usually the tail head, under the mane and underneath the horses’ abdomen. The mane is one of the sites where the flies feed.
Affected animals are very itchy, may rub intensely, and become restless. Prolonged rubbing results in crusting, scaling, skin thickening, hair loss and damage to the skin. Mane and tail hairs may be broken.
Treatment and management
A thorough clinical examination will be needed to rule out other possible causes of itching e.g. Oxyuris/pinworm, lice and food allergies. Good insect control is ESSENTIAL and should be the main focus of management:
– Stable the horse from 4.00pm until 8.00 am.
– Use specially developed rugs and hoods to provide protection.
– Apply sponge on fly repellents; often twice daily application may be required.
– Use Deosect; a longer lasting, pour-on repellent.
– Use a very fine fly screen over the stable door.
– Increase airflow by using a fan in the stable.
– Eliminate as many moist breeding grounds as possible; don’t allow puddles of standing water.
– Consider moving the horse away from wooded and wet areas.
Medication is available that can help decrease the severity but as yet there is no cure for Sweet Itch. There is an enormous variety of supplements on the market that promise to alleviate signs but none have been proven effective in a reasonable amount of horses.
* * Steroid medication: various types of this class of drugs are available from short to long acting with more or less risk of side effects (laminitis). This can be used in more extreme cases that are uncontrollable with other medication and management changes.
* There is a vaccination which was developed as a ringworm vaccine which seems to have as an added benefit a reduction of Sweet Itch signs, this was noted by Dutch vets using this vaccine. A course of 2 injections with 2 weeks in between should be administered before the start of the midge season (February-March). There is a UK study where after the vaccine 1/3 horses showed no more signs, 1/3 reduced signs and 1/3 showed no improvement.
We started using this vaccine 2 years ago and have had the expected results which have been a huge help for the afflicted ponies, Its time to vaccinate in February prior to this seasons midge. We impoet the vaccine so please contact the surgery to order your doses now so that you don’t miss out. Your horse would need to be seen by one of our vets for us to be able to administer the sweet itch vaccine.
The total cost of the vaccine is £150 (plus visit charge if we come to you) – about the same as a new Boet rug.
We can run a sweet itch vaccine clinic at the practice for those who can travel to us which will save you the visit fees too. We want your pony to have the best chance of a comfortable Summer.
As we have to import the vaccine we need to know towards the end of January each year if you wish us to order this in for you ready for the Sweet Itch season starting in March, so please do get in touch.
Tel: 01653 618303
Email: prescriptions@stationhousevets.co.uk