| |
|
Not all horses require a Boett hood but this one certainly did. |
| |
 |
|
Typical Sweet Itch damage to neck, withers and hips. |
Typical moderately severe damage to tail and hindquarters. |
The owner fitted one after this photo was taken! Within two weeks all sores had healed. |
A frustrating condition is Culicoides Hypersensitivity, more commonly known as Sweet Itch. 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.
Anybody who has owned a horse or pony susceptible to sweet itch knows how difficult it is to manage. A common misunderstanding is that the midges are biting the horse on its mane and tail where the majority of the itching takes place, whereas most of the bites will actually be on the belly and between the legs.
The worst times of the day are dusk and dawn. Avoiding turnout at these times is a good idea and overnight turnout with stabling early in the morning is probably best. Humid days also bring large numbers of midges out – so again it may help if you avoid turnout on humid days.
Treatment options remain very limited with cooling, soothing gels and creams containing aloe vera and tea tree and in severe cases steroid injections, being the main options. Prevention is the key to controlling this disease. There are a large number of proprietary fly sprays and some excellent developments with fly rugs using modern materials with belly flaps and face masks, which provide good protection.
Veterinary Researchers’ sweet itch hope
An article written in Veterinary Times June 2009 advises that scientists are a step closer to effectively tackling sweet itch in horses. Researchers at the University of Bristol ’s school of veterinary science have managed to isolate potential allergens in midge saliva, which they hope will lead the way to immunotherapy to treat sweet itch. Sweet itch causes extreme discomfort to horses, donkeys and ponies who experience a range of symptoms, including itching, hair loss, rashes and weeping sores. In a statement, the University of Bristol research team working on the project said: “We are now halfway there – we know what proteins are in midge saliva and how to manufacture them in sufficient quantities”. The statement explained that the next step would be finding out which proteins allergic horses responded to, and then providing them with regular doses of the protein to reduce their immune reaction. The statement added “We hope this can be achieved by feeding the midge proteins to the horse, so that its immune system responds to them as it would to normal food, and turns off the allergic response”.
Here at the practice we are extremely keen to keep clients up to date with developments on sweet itch treatments in an aid to assist those clients who’s horses suffer this debilitating disease. We will keep our website updated with any further advances in finding a treatment for sweet itch.
Sweet Itch Vaccination Trials
The 2007 sweet itch trials generally went well and the results are posted on the Sweet Itch Centre website. Trials with the sweet-itch “vaccine” continued in 2008 but were smaller in extent and limited to horses which had previously received capsules. A total of 183 horses were involved, the vast majority of owners returning questionnaires at the end of the season. Capsules were administered more frequently than in previous years: at least fortnightly and once weekly during periods of high midge challenge. Owners reported an Improvement or a Marked Improvement over the previous season in 48.6% of cases. Compared with the disease situation before the horses were involved in the trials, 72.2% of owners reported at least a 50% reduction in severity. For 2009 the Veterinary Medicines Directorate (VMD) has given permission to allow Sweet Itch capsules to be provided once again via the National Sweet Itch Centre. Ideally treatment should have commenced April 2009 or before. The cost is as before - £200 plus 15%VAT (total £230). The purpose of the trial is to gain vital feedback for Prof Stanford and his team at BioEos in the hope that a treatment can be found for this disease.
There is further hope with a brand new product * Cavalesse *
Cavalesse is a brand new product that is now available for the treatment of summer skin allergies such as sweet itch. It has been designed to make the surface of the skin more resistant to allergies and to reduce the production of histamine. Histamine is produced by the immune system in response to skin allergies and results in itchy skin. A pack of Cavalesse consists of an oral solution, which must be given on a daily basis, and a topical gel. A single pack will provide 3 months treatment for one horse. Again prevention is best – so action is required immediately as flies are already out!
A good quality fly sheet / sweet itch blanket is still the most important weapon in preventing sweet itch. Midges are at their most prevalent around dawn and dusk so prone horses should avoid being turned out during these times.
For further information on symptoms, causes, management and the results of the vaccine trials see the website
http://www.sweet-itch.co.uk/index.html or contact the Sweet Itch Centre on (Tel. 01352 771718, E-mail:- horses@sweet-itch.com)
|
