coughing horse - dust allergy?

[cobface]

Noticed the other day when i trotted my mare during warm up she had a cough about 4 times, bought her back to walk and carried on as normal and she was fine, the past couple of times i have rode her she has started to cough in trot for 3/4 times for the first trot then shes fine. Sje dosen;t do this everytime i ride, and its happened since she has been in over night. She has just come in of a night and this happens when i take her fresh out the stable to ride in the mornings. When out shes fine, also seems to happen around this time of year as i remember it happening a handful of times last autumn.
Does anyone elses horse get this? i am guessing its a sort of dust allergy problem so guessing that soaking hay is a good way to start and maybe changing her bedding (straw) if this doesn't work.
ps shes 5yrs.
Any suggestions/advice welcome

 

[cobface]

Anybody?

 

[nat88]

Know what you mean, had the same thing in Autum before, it clears up after the 1st frost, so maybe its a paticular spore? I have mined on cardboard bedding and have no problems, also have them on haylage too, it has made a hell of a differnce in their stables, to be honest my dust and spore allergies are very bad and I am not having any problems at all since I went as dust free as I can be. You could give that a try and see how you get on.