HORSE QUESTION: My chestnut, 2 year
old, Welsh/T.B. filly had this problem last year in the
summer too but it is really bad this summer. I am
guessing it is fly allergies and has gotton so bad she has
completely itched out the top of her tail, rubbed her poor
mane out until it is gone and has so many fly bites on her
belly, they bleed now. Even her face and chest is being
affected a bit this year. We have tried bathing her, and
putting oils and lotions on her, but nothing seems to
really help. Any suggestions?
ANSWER: You
are describing the symptoms of Sweet Itch (Queensland Itch) to a tee. An
annually recurring, seasonal, Pruritic Dermatosis of the horse, affecting the
mane, tail and belly regions, caused by an ALLERGIC reaction to "Culicoides",
who are most often called Midges, Sandflies, Punkies, or No-See-Ums, which are
very small, blood-sucking insects.
They fly only in the warm months of the year and
are most active before and during dusk, feeding often at the mane, tail and
belly region. The disease is a result of a Type 1 hypersensitivity reaction
(allergic reaction).
Usually only a small percentage of horses are
affected. Now some horses who are predispositioned to an allergic reaction to
this type of insect, may also have a reaction to the horn fly which affects
the Ventral Midline. Also the common Stable Fly which may cause a reaction on
the back, chest, head, neck, and legs.
Your Vet will best know which treatment to
instigate. Prednisolone or in severe cases, Dexamethasone. The dose should
be decreased gradually after 5 days, to the LOWEST possible dosage that
controls Pruritus. Also Topical Cortisone and Antibiotics MAY be helpful if
applied as a cream. Antihistamines are also effective in treating most
cutaneous hypersensitivity diseases in horses.
Very important is stabling the horse inside a
barn before and during dusk as these small blood sucking insects rarely enter
barns. Also the use of a fan blowing air around the horse also helps as
these type of insect are very poor flyers. A small amount of help can be
obtained by using fly repellent each day, just before dusk.
I have heard but not researched that some horse
people also believe keeping their horses in the barn during the rainy season
(each and every time it rains) may help prevent this getting as bad. As
continual rain causes its own set of skin problems with some horses.
I ruled out the horse being itchy and rubbing its
tail out because of a heavy infestation of internal parasites (worms) because
then only the tail head would be involved. I ruled out Lice or Mange because
it is only happening in the summer months. I ruled out Rain Scald as the
dermatitis isn't involving the entire top side of the horse and I ruled out
Ringworm as the irregular patches of loss of hair and roughened skin would be
entirely noticeable and not just in the tail, mane and belly region.