Crews were called to the incident on the outskirts of Upper Ventnor at Cooks Castle Farm shortly after 09:40 and are now on scene attempting to rescue the large animal.
The Incident Support Unit from Newport Fire Station, used for animal and water rescues, is in attendance with specialist equipment.
UPDATE @ 11:10 – The horse has been successfully rescued from the ditch by the Isle of Wight Fire and Rescue Service.
Vets are now assessing the animal, which is said to be an older horse.
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