Relationship Between Clinical Signs and Pulmonary Function Estimated by the Single Breath Diagram for CO2 (SBD-CO2) in Horses with Chronic Obstructive Pulmonary Disease

Department of Equine Internal Medicine, Faculty of Veterinary Medicine, University of Berne, Switzerland.
The Veterinary Journal (Impact Factor: 1.76). 04/2002; 163(2):187-95. DOI: 10.1053/tvjl.2001.0646
Source: PubMed


The pulmonary health of 66 horses was assessed by a clinical examination and simple supplementary diagnostic methods. Single breath diagrams for CO(2) (SBD-CO(2)) and derived lung function indices were used to determine pulmonary function. The clinical signs in different groups were related to the results of the lung function indices derived from the SBD-CO(2). In horses with moderate to severe chronic obstructive pulmonary disease (COPD), a significant relationship was found between the respiratory frequency and the ratio of Bohr's dead space to the tidal volume (VD(Bohr)/VT), and between the physiological dead space/tidal volume ratio (VD(phys)/VT) and the ratio of the alveolar dead space to the alveolar tidal volume (VD(alv)/VT(alv)), but no significant associations were found between the arterial oxygen tension (P(a)O(2)) and lung function indices derived from the SBD-CO(2). The occurrence of cough, the viscosity of tracheobronchial mucus and the amount of polynuclear neutrophils in tracheobronchial aspirates were significantly related to the expiratory tidal volume (VT), the total expired volume of CO(2) (VCO(2)), VD(Bohr)/VT, VD(phys)/VT and VD(alv)/VT(alv). We conclude that abnormal findings in these clinical parameters indicate a measurable ventilation and perfusion (V(A)/Q) mismatch which is reflected by increases in dead space, VD(Bohr)/VT and VD(phys)/VT as well as VD(alv)/VT(alv).

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    • "Många olika raser drabbas och de första symptomen på bronkiolit är nedsatt prestation samt sporadisk hosta (International Workshop on equine Chronic Airway Disease, 2000). Symptomen kommer ofta smygande (Herholz, 2002). Hostan kan med tiden bli värre, prestationsnedsättningen mer uttalad och hästen kan bukandas kraftigt med en så kallad " kvickdragsfåra " som följd (Robinson et al., 1996). "
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