Keratomas: causes and treatment options

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A keratoma is a rare, benign tumour that is found within the foot. It consists of abnormal masses of keratin (the main substance of hoof), which is deposited between the hoof wall and the underlying pedal bone.

What causes them?

We don’t know for sure, but they are thought to result from trauma or inflammation of the cells that produce horn.

Keratomas are most commonly found immediately below the coronary band, but they can develop anywhere within the foot.

They prevent the normal attachment of hoof to the pedal bone.

As the horn grows down from the coronary band, it can be pushed away from its attachment to the underlying pedal bone by the keratoma, resulting in an area of weakness at the toe.

This can allow infection to track up the white line and may cause abscessation within the foot.

The pressure created by the keratoma causes bulging of the hoof wall and resorption of the pedal bone, but in most cases the signs are subtle.

What are the treatment options?

Surgical removal of keratomas has been found to be more successful than conservative management.

Surgery is more easily achieved with the horse anaesthetised, but in some co-operative patients surgery can be performed under sedation with a nerve block to anaesthetise the foot and a tourniquet applied to control haemorrhage.

It is important to remove all abnormal tissue.

Can keratomas recur?

Keratomas can recur, but a recent study by the University of Liverpool vet school found that 25 out of 26 horses undergoing surgery returned to their intended use between six and 36 months after surgery (three of those horses required further surgery before returning to work).

For the full article on keratomas, see the current issue of Horse & Hound (21 January, ’10)

Watch video of keratoma surgery provided by World Horse Welfare

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