Pony has a slight cough WWYD.??

[Star the Fell]

For the last few days my pony has coughed once or twice whilst exercising. It is usually during the fist five minutes of warm up in walk, then again when we move up to trot and again in canter. Yesterday she coughed 3 times in the first half hour of an hours hack, today was just once as we set off.
Otherwise she is fine, no runny nose eyes bright. Eating well
The last couple of haylage bales have been late cut and are very seedy, so I am thinking that is perhaps the cause. I am mixing Dust x into her morning feed, but she is not too keen.
As she does need to work to keep her weight down I am planning to just hack out in walk for the next couple of weeks and give her every 3rd or 4th day off to see if it clears up.
Does this sound ok or would you do anything different?

 

[Jessey]

Mine get the occasional little cough, be it from a bit of a dusty bale, a seed scatching their throat or who knows what, so long as its not persistent and there are no other symptoms with it I normally just give some (horsey) cough mixture for a day or two too see it off

 

[Lemme]

are you in a position to soak the haylage for a few days ? if that does the trick then you know the cause ........

 

[Star the Fell]

I don't think she will eat soaked haylage. I have got some small bale haylage which I keep for emergencies - if we get snowed in in winter.
I will try her on that for a while. I will also ring the vet to check about riding her. I think I should be ok in walk as she walks around the field anyway.
How do you give the cough mixture Jessey? I am mixing some "Dust - X" in with her breakfast at the moment. I have some Lincoln cough mixture but would need to get a syringe to get it into her as she doesn't like it at all.