I know we have discussed Boett and other midge blankets, these do work for some horses who have pasture without woodland or something to either snag holes in the rug or available to rub it off.
For my pony Daniel I feed 100 grams of micronised linseed daily with 5 grams of pure garlic powder but would be happy to use flowers of sulphur if I had any left in the feedstore, just as Vitamin D is essential to the uptake of Calcium, sulphur plays it's role in allowing the beneficial copper and Omegas to be utilised.
Daniel also has a tablespoon of TURMERIC, twice daily when treating a sarcoid, now usually one tablespoon for maintenance. (Olive oil and pepper help with bioavailability.
I have fed raw, untreated linseed / flaxseed after clearing this with an equine surgeon veterinarian.http://www.thehorse.com/ViewArticle.aspx?ID=960
A University of Guelph Equine Research Centre (ERC) study indicates that flaxseed (linseed) can relieve symptoms of sweet-itch, an allergic skin condition more formally known as recurrent seasonal pruritis. Sweet-itch is a common complaint in many parts of the world. As many as 60% of horses in Queensland, Australia, are affected; more than 21% of horses in Israel; 26% of horses on the northwest coast of North America; and nearly 5% of horses in Japan.
Sweet-itch is triggered by the serum of tiny biting flies known as midges or no-see-ums (genus Culicoides). The bites cause intense itching, skin irritation, and patchy hair loss in horses. In North America, some 20% of imported Icelandic horses suffer from sweet-itch, largely because those horses build up no immunity to the fly bites in their native Iceland.
A study performed at the ERC demonstrated that flaxseed (linseed), fed as an oral supplement, can provide relief from the symptoms of allergic skin conditions. Flaxseed has long been recognized as a superior vegetable source of omega-3 fatty acids to treat many atopic (allergies likely to be hereditary) skin diseases in dogs. But while it is commonly fed to horses to improve the hair coat, the exact effect of these omega-3 fatty acids on the equine dermis (skin) is unknown.
In the ERC's double-blind study, six Icelandic horses with a history of sweet-itch (confirmed by a skin test with Culicoides extract) were fed ground flaxseed, or an equivalent amount of bran meal as a control, for 42 days. On Days 0, 21, and 42, the horses were injected with Culicoides extract, saline (as a negative control), and histamine (as a positive control, guaranteed to trigger a skin reaction), and the resulting reactions were assessed over a period of 18 hours. Samples of skin, blood, and hair were also taken to provide a fatty acid profile.
Horses on the flaxseed supplement showed significantly smaller skin test reactions to Culicoides serum after 42 days, indicating a less severe allergic response. Researcher Wendy Pearson O'Neill, MSc, also noted a reduction in the long-chain saturated fatty acids in the analyzed hair, which she says is an indication of changes in secretions from the skin. "By altering the fatty acids in the skin secretions, it's possible that certain populations of dermal microflora were affected, changing their ability to metabolize compounds such as histidine and trans-urocanic acid, which are involved in immune function," she explained. "This would reduce the overall immune response to Culicoides injection."
There were no significant changes in the fatty acid profiles of the skin or blood in treatment or control horses, and blood counts and biochemistry panels remained within the normal range. The ERC team concluded that flaxseed as an oral supplement is well-tolerated by horses, has no adverse side effects, and has considerable potential as a treatment for allergic skin disorders. http://www.thehorse.com/ViewArticle.aspx?ID=961
Horse owners wanting to take advantage of flaxseed's omega-3 content can rest easy. Flaxseed, or linseed, has a reputation as a toxic substance to horses when fed uncooked--earned because the seeds contain a small amount of cyanogenetic glycosides and enzymes that allow the glycosides to release cyanide. This poison is released when flaxseed plants are damaged by frost, drought, or processing. Since cyanide is readily absorbed in the GI tract, flax products could potentially prevent oxygen release in the blood, leading to sudden death.
However, we now know that glycosidase enzymes are destroyed in the equine stomach and small intestine long before they can trigger cyanide release. So it appears there is no risk of cyanide toxicosis when horses are fed raw flaxseed.