Vet needed in the Aude - respiratory specialist?


I am really struggling to get to the bottom of my horse's cough which has lingered since a sinus infection in February. He's had 2 loads of antibiotics, a herbal syrup for 14 days and loads of rest, lives out 24/7 and has had no hay for 4 months. On the 2 occasions the cough has completely subsided, I attempted to feed hay and each time the cough came back. It seems that hay might be the culprit but I really want a vet with experience in this area to have a look at him for a 2nd opinion.

If anyone can recommend a vet within a couple of hours radius of Quillan, Aude (11500) I would be EXTREMELY grateful!

Thanks in advance