Age Effects on Blood Gas, Spirometry, Airway Reactivity, and Bronchoalveolar Lavage Fluid Cytology in Clinically Healthy Horses
Article first published online: 16 FEB 2014
Copyright © 2014 by the American College of Veterinary Internal Medicine
Journal of Veterinary Internal Medicine
Volume 28, Issue 2, pages 603–608, March/April 2014
How to Cite
Pacheco, A.P., Paradis, M.R., Hoffman, A.M., Hermida, P., Sanchez, A., Nadeau, J.A., Tufts, M. and Mazan, M.R. (2014), Age Effects on Blood Gas, Spirometry, Airway Reactivity, and Bronchoalveolar Lavage Fluid Cytology in Clinically Healthy Horses. Journal of Veterinary Internal Medicine, 28: 603–608. doi: 10.1111/jvim.12318
- Issue published online: 15 MAR 2014
- Article first published online: 16 FEB 2014
- Manuscript Accepted: 6 JAN 2014
- Manuscript Revised: 16 NOV 2013
- Manuscript Received: 4 JUN 2013
- Aging in horses;
- Arterial blood gases;
- Pulmonary function testing
Despite the increasing number of geriatric horses attended by veterinarians, there is a lack of understanding of aging-related changes on the respiratory system of horses.
To identify aging-related changes on the respiratory function and bronchoalveolar lavage fluid (BALF) cytology of horses.
Fifteen healthy young adult (2–11 years) and 16 healthy aged (≥20 years) horses.
The respiratory system was examined by measurement of arterial blood gases (ABG), use of respiratory inductive plethysmography (RIP) for assessment of breathing pattern and ventilatory parameters, histamine bronchoprovocation, and BALF cytology.
No significant differences were detected with regard to values obtained by ABG or bronchoprovocation of young adult and aged healthy horses. In aged horses, there were significant differences in mean ± SD of the following parameters when compared to young horses: prolonged expiratory time (Te) measured by RIP (3.9 ± 1.5 s versus 3.0 ± 0.6 s), decreased percentage of alveolar macrophages (40.6 ± 11.3% versus 53.5 ± 9.6%), and increased percentage of lymphocytes (53.4 ± 9.5% versus 43.9 ± 11.0%). No correlations between airway reactivity and ventilatory parameters, ABG, or BALF cytology were found in this asymptomatic population.
These results suggest that aging does not cause changes in the results obtained by ABG, most RIP-derived variables, and bronchoprovocation in the horse. A decreased percentage of macrophage and an increased percentage of lymphocytes in the BALF cytology may be expected in the asymptomatic geriatric horse and may be a result of aging.