The scenario might sound familiar: You take a couple laps around the arena with your horse, and suddenly he starts coughing so hard he yanks the reins out of your hands. You let him rest but he doesn't seem to be able to catch his breath. Could he have picked up a respiratory infection at the last horse show?
This is a typical case an equine veterinarian would encounter. The owner brings a horse in to a referral clinic, reports a cough and exercise intolerance, and might immediately ask for him to be put on antibiotics. As veterinarians, our job is to decide if antibiotics are necessary and beneficial, particularly since we're seeing increasing resistance of bacteria to these drugs. So how do we decide? And if it's not a bacterial infection, what else could it be?
Your horse's recent history is incredibly relevant to the diagnosis. Be prepared to answer a barrage of questions about new hay or bedding, turnout changes, any new horses in the barn, recent travel, vaccination status, appetite, what triggers the cough, whether it's dry or wet, or if there is any discharge, among other inquiries.