Which symptom is NOT typically associated with Chronic Obstructive Pulmonary Disease (COPD) in horses?

Bright red mucous membranes are not typically associated with Chronic Obstructive Pulmonary Disease (COPD) in horses. In horses affected by COPD, which is also known as recurrent airway obstruction or heaves, you would expect to see symptoms arising from impaired airflow and damaged lung tissue. Common signs include a severe cough, respiratory distress, and heavy expiration as the horse struggles to breathe.

Bright red mucous membranes are often indicative of increased oxygen levels or hyperemia, which can occur in other respiratory conditions or physiological states but are not characteristic of the hypoxemic conditions usually observed in COPD. In horses with COPD, the ongoing airway inflammation and obstruction typically lead to a lack of efficient gas exchange, resulting in a bluish tint to the mucous membranes due to insufficient oxygen (cyanosis) rather than the vibrant red indicative of adequate oxygenation.