How to Stop Sweet Itch (Summer Itch) From Driving You and Your Horse Crazy!

Summer seasonal recurrent dermatitis (SSRD), commonly called sweet itch or summer itch, is caused by a horse’s allergic reaction to the saliva of a biting gnat known as the Culicoides midge. Many people refer to them as “no-see-ums.” These bothersome fellows are active from April through October. They live and breed in ponds, marshes, and areas where water is standing and stagnant. Gnats can travel up to half a mile to find a good meal. They tend to be most active during the hours around dawn and dusk.

It takes about 48 to 72 hours after the first gnat bite for your horse to start showing symptoms. The severity of the reaction increases from year to year, as your horse becomes increasingly more sensitive to the insect’s saliva. Dorsal feeders are the most common gnat; they feed on the skin around the ears, poll, mane, withers, rump, and tail head. Less common are the ventral feeders, who cause problems on the face, chest, and belly.


The symptoms of SSRD or sweet itch are hard to miss. Horses will constantly rub affected areas as a response to the intense itching. In the acute phase (early phase) the skin will become red and inflamed, and devoid of hair. Crusting and weeping sores may be present. In the chronic phase (later phase) the skin will thicken, blacken and become wrinkled. Sparse, course hair may be present. Once winter comes, the area completely heals up.

There are several measures you can take to limit your horse’s exposure to these annoying insects.

  • Install fine mesh screen in your barn to keep the gnats out. (This is not always practical, however.)
  • Circulate the air with ceiling and stall fans to discourage the gnats from hanging around.
  • Keep horses stalled an hour prior to and after dawn and dusk to reduce exposure to the bugs when they are most actively feeding.
  • Keep stables at least a half mile away from marshes and swamps.
  • Ensure pastures are well-drained to reduce stagnant water from collecting.
  • Keep water tanks clean and filled with fresh water.
  • Use insecticides and repellents to kill gnats and keep them off your horse.
  • Use a fly sheet with tail flap and hood to cover vulnerable areas.

Treatment and prevention

The sooner you notice sweet itch and start on a program of treatment and prevention the better off your horse will be. A horse can do a lot of damage in a short period of time when they start rubbing manes and tails.

When you first notice symptoms, take immediate action to reduce your horse’s exposure to these nasty gnats by following the recommendations above. Contact your vet and ask him or her about corticosteroid and antihistamine treatments.

Coating the itchy area daily with an oily substance, like baby oil or Skin So Soft, is often beneficial. Midges don’t like the oily film and will avoid it. Be sure to reapply the oil often, as it tends to wear off as the day goes on.

Be careful with preparations that contain eucalyptus oil, citronella oil, tea tree oil, or mineral oil, as they may cause additional skin irritation. Try them somewhere else on your horse first. Watch the area for 24 hours, noting the appearance of any heat or swelling. Don’t use any preparation that causes irritation.

Supplementing with omega-3 fatty acids has been proven to reduce skin inflammation and mitigate allergic response. Fish oils contain the highest level of beneficial omega-3 fatty acids. When adding a fish oil supplement to your horse’s diet, do so slowly. Add a small amount at a time. In the beginning pour the oil on the feed and let it sit for 30 minutes before mixing it in so the smell is less powerful. Most horses will readily eat fish oil once they become accustomed to the new flavor.



  • How much fish oil per pound of horse is required ?

    • Karen

      Dear Wayne,

      Not all fish oils are the same quality. We suggest you use a marine-based omega-3 fatty acid supplement that provides EPA and DHA, and that has been developed for horses.

      We recommend Contribute ( Feed 1 to 2 ounces per day.


  • Linda edwards

    Use mtg

    • Toshia

      MTG made my horse more itchy the way it attracts dirt and debris.

  • Mel

    We give our horse garlic powder with their food and it has helped keep flys, ticks and knots to a minimum as well as giving them a beautiful coat

    • Karen

      Feeding garlic has long been touted to repel insects, but no scientific trials have been done to verify this claim. On the other hand, several studies have shown that garlic (and other alliums, plants in the onion family) contain the chemical n-propyl disulfide that can cause serious problems. N-propyl disulfide changes the makeup of the enzymes found in red blood cells. This change leads to a depletion of another chemical called phosphate dehydrogenase (PD), which protects the cell from oxidative damage. When the PD levels get low enough a bubble called a Heinz body forms on the outside of the cell. When these blood cells are filtered through the spleen they are recognized as damaged and are removed from the horse’s body. If enough red blood cells are damaged and removed it can cause a condition known as “Heinz body anemia.”

      The toxic dose of n-propyl disulfide is not known. One study showed that horses fed 200 or more grams per day of garlic powder developed Heinz body anemia. Another study showed when horses were fed as little as 16 grams per day over an 83-day period, blood chemistry was altered.

      The National Research Council states that feeding 7.5 grams per day of garlic powder should not lead to problems in normal circumstances. However, many vets feel the toxic effects of n-propyl disulfide may become a problem in horses that are fed these low doses on a regular basis. The resulting anemia may not be readily noticeable, but the horse can suffer from reduced stamina, lower energy levels, and a decreased resistance to disease.

      In human research, when garlic oil was applied topically at a 1% dilution it had a 97% effect in repelling insects. Applying diluted garlic oil to your horse may be more effective and safer than feeding garlic.

  • Hi,
    really appreciate all your ideas for dealing with.sweet itch, my mare has only a small.patch at the base of her mane, next to her withers, so.will.try the remedies suggested.
    Many thanks for your advice.
    Suzan. Greek Islands.

  • It’s amazing how fast this itch can turn into a real problem. I talk to my vet at the beginning of every summer to get antihistamine treatments.

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    • Flicka

      My horse is a brown buckskin and suffers summer itch, we are not living at our farm where he is staying until five weeks from now. He is rubbing out his mane and top his tail as well as bites along his neck near the main and wither, if you have any tips please tell me I have tried things but non have worked. From flicka.

      • Karen

        Hello Flicka,

        Definitely follow the recommendations in the above article as soon as you can. Barriers such as flysheets with hoods and tail covers will reduce exposure and can be worn full-time as long as horses are checked daily. I would start your horse on Contribute as soon as possible. The Omega-3 fatty acids in Contribute will help support healthy inflammation levels, which mitigate the severity of allergic reactions. Since your horse has active inflammation it may take a few weeks to see results.

        You can also contact your veterinarian and discuss medical options such as steroids or antihistamines that will reduce the current inflammation quickly while you begin supplementation and take other preventative measures. In the future, since you know your horse has this sensitivity, be proactive; don’t wait until you see signs of irritation to take action. Start Contribute a month prior to the appearance of no-see-ums.

        Best regards,

  • Baillie

    My Red Mare, has hives, and itches, and is losing her hair…well she came to me this way and under weight, I have put ALOT of weight on her and I have tried everything to clear up her skin 🙁 nothing so far is working. She not use to being handled a whole lot, so a fly sheet is out of the question (for now). she is only 11 years old but looks like she 30 cause her skins is so wrinkly and dry and just horrible looking my poor Red. I will be trying Diaper Cream. Ill do anything to try and help my girl get some relief. She has a vet Appoint for Wednesday the 27th to get a allergy shot, but until then and in-between I need help for my Mare.
    Thanks so much

    • Hello Baillie Jean,
      Skin and hair coat problems can be very frustrating and hard to clear up. Our first recommendation is always to consult a veterinarian for treatment options, which you have already done. Please follow the recommendations in this article as they can help tremendously.

      With regard to nutritional support, to help in the reduction of overall inflammation and mitigate any allergic response Red might be having, I recommend providing additional omega-3 fatty acids in the diet. Omega-3 fatty acids are research-proven to be anti-inflammatory in nature. Kentucky Performance Products’ Contribute omega-3 fatty acid supplement guarantees a level of 10,780 mg of omega-3 per ounce. A complete complement of omega-3 is supplied: 3,210 mg of EPA and 2,320 mg of DHA, both from high-quality fish oil and alpha-linolenic acid in the form of flax oil. Contribute guarantees an 8:1 ratio of omega-3 to omega-6 fatty acids.

      In your situation I would start feeding Red one ounce of Contribute per day. Since Contribute is primarily fish oil it might be a flavor Red is unaccustomed to. If necessary, mix Contribute with some applesauce or yogurt until she gets used to the flavor. When introducing Contribute to the diet, do so slowly over 7 days. Start with a small amount (1/4 tablespoon) mixed in the feed and increase the amount daily until you reach the full dose. Once a horse becomes accustomed to the new taste they will eat Contribute with no problem. One gallon of Contribute is a 128-supply at 1 ounce per day. You can feed up to 2 ounces per day, in which case you would feed 1 ounce per feeding.

      To help your girl strengthen her immune system (which will help in the battle with skin dermatitis) and support muscle development as she gains condition, I would recommend 3 scoops (3,000 IU) of Elevate Maintenance Powder per day. Elevate contains a highly bioavailable source of natural vitamin E. Natural vitamin E is a critical nutrient often missing from the equine diet, as its primary source is fresh green grass. Horses grazing 18 or more hours a day on good pasture can meet their maintenance requirements, but given Red’s challenges, her requirement is more than likely much higher and she many even be battling a deficiency given her past history. You can split the Elevate amount into 1 ½ scoops per feeding or feed it all at once. Once you have her skin cleared up you can drop the amount fed down to 2 scoops (2,000 IU) per day. If she is on good pasture for at least 12 hours per day, then reduce the amount to 1 scoop (1,000 IU) while pasture is available. Increase the amount back to 2 scoops (2,000 IU) in the winter once the pasture dries up. A 2-lb jar of Elevate Maintenance Powder will last you 43 days when feeding 3 scoops per day.

      I hope this helps clear up you mare’s skin problems. If you have any further questions, please let me know.
      Karen at KPP

    • Sylvia

      Try neem oil it works great. You can purchase it at health food stores.

  • Dianne Van Dreel

    could petroleum jelly be used?

    • Petroleum jelly, like mineral oil can cause irritation so try it on a small area first to see if it irritates your horse.

  • Niki

    My horse has had some patches on her forehead appearing, they are dry and crusty with sores appearing in them, like its described above. We have had her in a pasture with a slew in it, she spent most of her day in the still water. Once we discovered her patches, we moved her to a new pen away from the water. We are using A product named M-T-G on her head, and no know improvement have been showing. Would a fly mask be an ok cover for her face?

    • Hi Niki,

      I suggest you contact your veterinarian and have him/her rule out a bacterial infection or other skin condition. Using a fly mask to help keeps the bugs off the irritated area may be helpful. When using a fly mask be sure it does not cause further irritation by rubbing the problem area. Always use a clean, dry fly-mask to reduce the incidence of secondary bacterial or fungal infection. I keep two fly masks handy so that I always have a clean one available. Wash your fly masks frequently in soapy water, rinse well and air dry.

      Karen J Isberg

  • Anne

    Oatmeal Paste: “Oatmeal; Oat flour; water”; mix to proper consistency; apply dry rinse; (put this right under the mare’s tail esp around where she rubs; apply daily.”; put this around the mane too; the oatmeal “dries up any mites; fungus; no see ums.

  • Anne

    “I think the Mare might try the Oatmeal based “poultice”; the Oatmeal will dry mites”; I doubt “No See Ums” could get thru a thick Oatmeal plaster: I would try mixing Oatmeal Flour and water; apply around and under the tail; allow to dry rinse.

    At the very least; the Mare will get Magnesium from the Oatmeal. Paste;
    Thanks “Kentucky Performance”; I think your Nutritional Minutes are the best!”AR@

  • Anne

    In some horses, good old-fashioned zinc oxide (diaper rash ointment) is soothing and also acts as a barrier against the insects.

    I have used Zinc Ointment successfully on my own skin; the Zinc works wonders!!
    Maybe the mare rubs her tail because she has some type of “mites”. I have heard when a Mammal is susceptible to Bug Bites they might get “B-Complex Vitamins!!

  • Susie Ardron

    What can I use to calm mane tail rubbing

    • It is important to identify what is causing the tail rubbing. I would suggest having your vet check the horse to rule out things like pinworms and bacterial infection. If the tail rubbing is caused by insect hypersensitivity, the best way to stop it is by limiting exposure to the insects, as outlined in the article. Supplementing with omega-3 fatty acids (Contribute) will also help mitigate the skin reaction and calm the itching. There is some evidence that oatmeal-based preparations will reduce itching, but it won’t help much if the bugs are still biting the horse. In some horses, good old-fashioned zinc oxide (diaper rash ointment) is soothing and also acts as a barrier against the insects. Check in with your vet, as he or she can prescribe topical and systemic steroid treatments if necessary.

      • Eva Andersson

        Listerine will stop then tail rubbing , just make sure you don’t get it on her private parts if its a filly, it will sting a little

        • Karen

          Desitin (diaper rash ointment) is another option. It is messy but it repels the midges, it is waterproof and also soothes the skin. Apply daily in trouble spots.

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