Non-invasive monitoring of changes in exhaled markers of airway inflammation in Thoroughbred racehorses

Cathcart, Michael Peter (2016) Non-invasive monitoring of changes in exhaled markers of airway inflammation in Thoroughbred racehorses. MVM(R) thesis, University of Glasgow.

Abstract

Exhaled breath (EB) and exhaled breath condensate (EBC) contain numerous volatile gases and a wide-array of non-volatile compounds, several of which have been investigated as markers of lower airway inflammation in human and veterinary medicine and have been used to diagnose and monitor diseases associated with pulmonary inflammation. The identification of reliable biomarkers within EB and EBC is an active research focus with the common goal of establishing non-invasive and repeatable assessment of respiratory health and disease in mammals. The application of EB and EBC analysis holds considerable appeal in the investigation of respiratory disease in Thoroughbred racehorses, as inflammatory airway disease (IAD) is a common cause for poor performance in this population of animals.

This study documented that EB and EBC samples can be safely collected from Thoroughbred racehorses in their own environment, without adverse effect or interference with the horse’s training regimen. The use of off-line collection and analysis of exhaled gases via chemiluminescence is suitable for the measurement of exhaled carbon monoxide, but is not appropriate for analyzing exhaled nitric oxide in horses.

Significant changes in the concentration of exhaled CO and the pH of EBC occurred in response to strenuous exercise and when exercising in different environmental temperatures. Exhaled CO was associated with tracheal mucus score (and the number of neutrophils in the mucus) and EBC pH was significantly different in horses with evidence of neutrophilic IAD compared to horses without IAD.

Numerous physiological and environmental variables were identified as confounding factors in the assessment of both exhaled CO and EBC pH, with respiratory rate prior to EB collection, and during EBC collection, consistently identified as an explanatory variable influencing the concentration of exhaled biomarkers. Further studies in EB and EBC analysis in horses need to focus on objectively accounting for key respiratory dynamics during sample collection.

• Item Type: Thesis (MVM(R))
• Qualification Level: Masters
• Additional Information: Supported by funding from the Horserace Betting Levy Board, and supported by the School of Veterinary Medicine, University of Glasgow.
• Keywords: Equine, lower airway inflammation, exhaled breath, exhaled breath condensate.
• Subjects: S Agriculture > SF Animal culture > SF600 Veterinary Medicine
• Colleges/Schools: College of Medical Veterinary and Life Sciences > School of Biodiversity, One Health & Veterinary Medicine
• Supervisor's Name: Love, Professor Sandy and Sutton, Doctor David
• Date of Award: 2016
• Depositing User: Dr Michael P Cathcart
• Unique ID: glathesis:2016-7463
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 05 Jul 2016 07:36
• Last Modified: 12 Jul 2016 09:20
• URI: https://theses.gla.ac.uk/id/eprint/7463