This study investigates whether dogs with tracheal collapse have increased levels of blood inflammatory markers. Dogs with tracheal collapse can experience significant airway narrowing and thus airflow limitation. This can lead to mild or intermittent changes in oxygenation which may stimulate inflammation throughout the body. The research team aims to determine if inflammation occurs in dogs with tracheal collapse, and whether markers of inflammation could be used in the future to provide information about disease progression or response to therapy.