Does this horse sound like it has COPD (Chronic obstructive pulmonary disease), opinions?

My friend i away for a month and i'm looking after her horses, she had bought a haflinger mare 14yro at the end of the winter in 2007, they live out all year, but i have noticed that when she is around hay or tied up, she tends to wheeze and cough quite often. I've asked my friend and she said she did cough a little last winter, but cleared up after a month. I'm worried she may have COPD, she is fed on hay in the winter, the hay is watered over with a hose (but i've started to soak it in a bucket for 20 minutes, as using a hose doesn't wet all of the hay) But i've noticed that she is on the think side, she coughs when near a dusty environment and she wheezes at the end of exhaling. It may be something or it maybe nothing, what do you all think? by the sound of it i think it may be a recurrent cough that comes back every winter, she sometimes wheezes when shes around a high pollen area, but its not bad. what do you think? or what else could it be? Is there anything i can give her?