A Mare Itch

Is your horse nagged by an itchy skin condition where the poor creature is rubbing itself constantly, causing hair loss and skin damage? If so, it is likely to suffer from a condition commonly called 'Queensland Itch' and if the disease is not treated, your horse's life may be a misery.

What Causes Queensland Itch?

The cause of Queensland Itch is an allergy, referred to as a hypersensitivity, to the bites of sand flies (midges).

Not all horse suffer the sensitivity but those that do will rub themselves so much that they cause injury to their skin. The cause is actually an allergic reaction to chemicals in the saliva of the midge. This reaction releases specific chemicals into the skin and these chemicals cause an irritation that in turn causes the horse to scratch and rub.

In many ways, it is similar to fleabite allergy that dogs suffer where, when bitten by a flea, a dog will chew and rub itself excessively.

Queensland Itch is a summer problem and is worse when the weather is hot and humid, just like it has been in the last few weeks. If still or stagnant water is nearby, the condition will be worse as this the medium in which the midges breed.

You should suspect that your horse has Queensland Itch if it develops a reoccurring, itchy skin condition every summer and if the itching occurs mainly around the butt of the tail and around its mane.

What Affect Does Queensland Itch Have On Horses?

The effects on the horse can be dramatic. It will spend hours rubbing itself against any fixed object. Hair loss is common in the areas that the horse is rubbing. This is usually along the midline and in the mane. The hairs will be coarse, broken and stubbly and will often be standing on end. Crusts, scales and scabs appear in the coat, especially on the butt of the tail and around the ears.

While horses do not die from Queensland Itch, badly affected horses are of little use as working or pleasure animals as the itching makes them difficult to work. The damage to their coat also makes them look terrible.
Controlling Queensland Itch

Solving the Problem

To control the problem, repelling the midges is important but severely affected horses will need medication. The following points summarise the needed treatments.

• Eliminate midge breeding areas

As midges breed in still or standing water, eliminate unnecessary reservoirs of old stagnant water.

• Stable and rug horses

Midges mostly feed at dawn and dusk, so keeping the horse in a stable at these times will help and you will have much greater success if the stable is fly-screened.

A full body rug will effectively protect the horse but some itchy horses will also damage the rug through their rubbing so anti-inflammatory medication may be needed to reduce the underlying irritation when the rug is installed.

• A Breezy solution

The midge is not a very strong flyer and does not like wind, so placing a fan in the stable may stop the bugs from getting to your horse. For the same reason, having the stable on high ground helps as any natural breeze that is flowing will waft through the stable and give the biting bugs a hard time.

• Repel the Midges

Treating the horse with animal-specific insect repellents is often useful. While there are several on the market, my horsey colleagues at Samford advise the use of a permethrin-based repellent called Brut. This is applied to the horse with an applicator mitt that comes with the product.

As 'Queensland Itch' is a seasonal condition, if you are using a repellent, start it in spring and continue for the summer months, but your horse should not need it in winter.

• Seek Veterinary treatment

If the condition is severe, veterinary treatment may be needed. This may include anti-inflammatory creams or injections to reduce the itching and, if infections are present in the damaged skin, your vet may need to prescribe antibiotics.

• Move the Horse

If you have a seriously-affected horse, the only remedy is sometimes to move the horse to an area where the midges are not present.

Other conditions can cause itching in horses and your veterinarian may have to help with a diagnosis. A variety of contact allergies and even a pinworm infestation can cause a similar problem.