34th Annual Scientific Meeting proceedings

Objectives:

The chronic hypoxia experienced by brachycephalic dogs that exhibit Brachycephalic Obstructive Airway Syndrome (BOAS) is fairly described, but the systemic repercussions are unclear yet. These dogs are used as models of Sleep Apnea Syndrome (SAS) in human studies since they share breathing and sleeping characteristics. Recent studies show that human patients affected by this syndrome have high serum concentrations of Hypoxia-inducible factor (HIF-1α). We hypothesize that the same would occur in dogs with BOAS.

Methods:

Fifty two clinically assessed as healthy – except for clinical signs related to BOAS –  brachycephalic dogs were graded (0-3) according to laryngeal auscultation before and after the exercise test. Their blood sample was collected afterward, and the HIF-1α quantification was made by ELISA testing. The results considered normal by Levene tests, were analyzed with one and two-way ANOVA and Tuckey’s post hoc, in RStudio, with significant p-value ≤0.05.

Results:

Dogs graded as 0 (no clinical signs of BOAS) had higher levels of HIF-1α (76.6 ± 28.2) than the ones graded as 3 (52.4 ± 26.8). Additionally, it was observed that these animals also had alterations in arterial and venous pH, lactate levels, and venous PCO2.

Conclusions:

These results suggest that the regulatory mechanisms of dogs affected by BOAS may be different from those in human patients with SAS or even that they have possibly lost their sensibility to this protein due to the congenic character of the syndrome.

Financial Support: São Paulo Research Foundation 2023/12747-5