Sound spectography in the diagnosis of equine respiratory disorders: a preliminary report

Authors: Brennan M, Kirkland J, Barnes GRG, Goulden BE
Publication: New Zealand Veterinary Journal, Volume 27, Issue 7, pp 145-146, Jul 1979
Publisher: Taylor and Francis

Animal type: Horse, Livestock
Subject Terms: Diagnostic procedures, Ear/nose/throat, Respiratory system
Article class: Scientific Article

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Abstract: One problem in the diagnosis of subclinical roarers is that abnormal auditory signals occur only during a fast gait, and these fade quickly. This paper offers a novel technique to assist this problem. Sound recordings were obtained from five horses following exercise; two roarers, two non-roarers, and one suspected roarer. These signals were converted into spectrograms by Rayspan processing. All frequencies in the 0 to 2.25 kHz range during both inspiration and expiration, as well as occasional noises in the 2-4 kHz band, characterised roarers. Signals from non-roarers consisted of frequencies in the 0 to 2 kHz range with long quiet periods, especially during expiration. An explanation for these phenomena is offered, and supported by diagrammatic cross-sections of equine upper-respiratory tracts. It is suggested that the present technique could assist in the diagnosis of subclinical roarers, estimated to be between 20 and 40% of the competitive horse population.

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