Evaluation of Pulse Oximetry in Healthy Brachycephalic Dogs

Brachycephalic airway syndrome (BAS) is characterized by increased upper airway resistance due to conformational abnormalities occurring in brachycephalic dogs (BD). In this prospective study, we evaluated pulse oximetry (SpO₂) and arterial blood gas values in 18 healthy BD and compared these values with those of 18 healthy mesocephalic and dolichocephalic dogs (MDD). All dogs were assigned a BAS score based on an owner questionnaire. Inclusion criteria included presentation to the hospital for a problem unrelated to the respiratory system and unremarkable blood analyses and physical examination. In awake dogs, SpO₂ values were obtained from a minimum of two sites. Dogs were then sedated, and SpO₂ values were obtained again concurrently with an arterial blood gas sample. The SpO₂ values were significantly lower in BD compared with MDD, but there were no statistically significant differences between BD and MDD for any arterial blood gas parameters. Based on the BAS score, BD who were moderately BAS-affected (n = 5), had significantly lower arterial saturation of hemoglobin with oxygen values on arterial blood gas when compared with MDD (n = 18). Although BD had statistically lower SpO₂ values than MDD, the mean SpO₂ values for both groups were within the normal range.