Warble

Symptoms

A hard rounded anthill-shaped lump found upon the horses back, often in the saddle area. There is a distinct hole on the top to allow for the larvae to breathe which fluid may ooze from.

Cause

Warble is now rarely found in the horse due to a long campaign to eradicate it. It is caused by the warble fly laying its eggs upon the horses’ skin, usually on the legs. The eggs then hatch and the larvae burrow into the skin and migrate upwards to the horses back. They create a hole so they can breathe, and then will develop over a period of time. It is unable to complete its life cycle whilst living on the horse, and will usually die in the skin.

Treatment

A regular worming programme which includes ivermectin will prevent warble by killing the larvae before it migrates. If they have already reached the back, it may be possible for your veterinary surgeon to remove them by gently widening the breathing hole or by using a poultice which may draw the larvae out. Surgery may be required to remove the lump if the larvae is too developed.

Please remember this information is provided as a guide only and professional advice should be sought before any diagnosis or treatment is applied.