I won’t get to barn til this evening to check it out, but it sounds like we have the same stuff.
Timeline:
He developed a wet cough/exercise intolerance within three days, called vet, she took tracheal wash and put him on SMZs until we got cytology. His blood work was normal, no temp, appetite fine, bright and eager, just coughing up phlegm.
SMZs didn’t appear to work after 10 days, so it was assumed IAD problem and not pneumonia. SMZs stopped and Ventapulim started. No results on Ventapulim. Fever spiked on 4th day without SMZ. Decided SMZs must have been keeping an infection subclinical and it could be pneumonia after all. Cytology had suggested gentamicin, so we switched to that and stopped ventapulim.
Still had a cough after four days of gentamicin so we opted for hospital to do BAL and lung xray. While at hospital, still on gentamicin, his cough and exercise intolerance cleared in two days. We did the BAL, xrays, CBC and blood chemistry panel. Xray showed some mild infiltrates, BAL showed high MAST cell, everything else normal.
Diagnosis is IAD, and I was sent home with instructions to remove dust, put him on one week of oral antibiotics and concurrently on tapering dose of prednisilone. They thought he did experience a low level pneumonia, but that IAD was the main probem due to high MAST cell reading. I now understand that the antibiotics are not for residual pneumonia, but are prophylatic with the prednisilone since it lowers the immune response.
Everything I have read about IAD says it comes on slowly. This didn’t. He had been at that barn for 18 months, exposed to the hay, dust, etc. The only thing new is that he was backed for the first time in June and was beginning very easy ridden work, maybe 20 min 3x a week. So his workload increased slightly from ground school and roundpen and turnout, but definitely not vigorous.
I might just be an owner in denial, but it seems strange to me.
My plan is to hold off on giving the prednisilone until he’s had a couple days at the new (less dusty) barn – I want to see if the new barn causes him to react with a cough. I’m afraid if I start the pred, I might be masking a reaction and in three weeks I’ll be doing this again.