Aim of the study:
To detect the rate of spontaneous augmented breaths (SAB) in adult ponies at rest as well as the influence on succeeding breathing cycles.
Material and Methods:
Breathing patterns of six adult ponies, free from clinically evident respiratory diseases were recorded during two consecutive hours by means of the respiratory ultrasonic plethysmography. The ratio of Vt before the SAB to Vt of the SAB (Vt(TAZ)/Vt Ratio) and the rate per hour was calculated. Additionally the breathing frequency, the occurrence and the duration of of apnea episodes after deep breaths were determined als well as the percental rate of apnea relevant to the entirety of deep breaths.
The average SAB frequency was 6,0 ± 1,3 per hour with an average amplitude increase of 4 ± 0,5 times Vt. Five out of six ponies developed apnea episodes immediately after the SAB (average duration 10,3 ± 5,3 seconds) with 38% followed by apnea.
This study indicates that SAB are part of the physiologic breathing pattern in adult Shetland ponies and influence consecutive breaths due to genesis of apnea