Evaluation of Arterial Blood Gases and Arterial Blood Pressures in Brachycephalic Dogs

• Published in: Journal of veterinary internal medicine 2012-07, Vol.26 (4), p.897-904
• Main Authors: Hoareau, G.L., Jourdan, G., Mellema, M., Verwaerde, P.
• Format: Article
• Language: English
• Subjects: Animals; Arterial Pressure - physiology; Blood Gas Analysis - veterinary; Carbon Dioxide - blood; Chronic hypoxemia; Craniosynostoses - blood; Craniosynostoses - physiopathology; Craniosynostoses - veterinary; Dog Diseases - blood; Dog Diseases - physiopathology; Dogs; Electrolytes - blood; Hematocrit - veterinary; Hypertension; Hypertension - blood; Hypertension - physiopathology; Hypertension - veterinary; Oxygen - blood; Peripheral chemoreflex; Regression Analysis; Surveys and Questionnaires
• ISSN: 0891-6640; 1939-1676
• DOI: 10.1111/j.1939-1676.2012.00941.x

Background Brachycephalic dogs (BD) are prone to congenital upper airway obstruction (brachycephalic syndrome, BS). In humans suffering from sleep apnea, upper airway obstruction is known to cause hypertension. There is no information regarding the influence of BS in dogs on cardiorespiratory physiology. Hypothesis BD are prone to lower PaO2 , higher PaCO 2, and hypertension compared with meso‐ or dolicocephalic dogs (MDD). Animals Eleven BD and 11 MDD. Methods After a questionnaire was completed by the owner, a physical examination was performed. Height and thoracic circumferences were measured. Arterial blood gases, electrolyte concentrations, and packed cell volume (PCV) were measured. Systolic (SAP), mean (MAP), and diastolic (DAP) arterial blood pressure recordings were performed. Results A total of 7 French and 4 English bulldogs met the inclusion criteria. The control group consisted in 6 Beagles, 2 mixed breed dogs, 1 Staffordshire Bull Terrier, 1 Parson Russell Terrier, and 1 Australian Cattle Dog. Statistically, BD had lower PaO2, higher PaCO2, and higher PCV when compared with controls (86.2 ± 15.9 versus 100.2 ± 12.6 mmHg, P = .017; 36.3 ± 4.6 versus 32.7 ± 2.6 mmHg, P = .019; 48.2 ± 3.5 versus 44.2 ± 5.4%, P = .026, respectively). Also, they had significantly higher SAP (177.6 ± 25.0 versus 153.5 ± 21.7 mmHg, P = .013), MAP (123.3 ± 17.1 versus 108.3 ± 12.2 mmHg, P = .014), and DAP (95.3 ± 19.2 versus 83.0 ± 11.5 mmHg, P = .042). BD with a PaCO 2 >35 mmHg were significantly older than those with a PaCO 2 ≤35 mmHg (58 ± 16 and 30 ± 11 months, P = .004). Conclusion Results of this study suggest that some BD are prone to lower PaO2 , higher PaCO 2, and hypertension when compared with MDD. Age may be a contributing factor.