The longest tail on a horse is 381 cm (12 ft 6 in) and was measured on the mare JJS Summer Breeze on 23 August 2007. She is owned by Crystal and Casey Socha of Augusta, Kansas, USA.

Two slightly different measurements were provided. One was 12 ft 7 in by Mrs Williams, one of the witnesses, the other the above, by mr Mohney, a Vet. We decided to go with the measurement that was provided by the Vet because he is the expert in the field.