The last two nights Cash has done his shuffling western pleasure jog for maybe 2-3 minutes each way in the round pen. If I ask for extension or a canter, I'll get a few strides from him before he stops for several hard, loud, full body involved coughs. He seems really winded/out of breath, but other horses are out riding unphased. I haven't been pushing him hard to this point, but he should be in good enough condition to handle 5 minutes of light trotting, despite the heat. There is no eye or nasal discharge, no swollen glands, he's eating & drinking, pooping solid, and otherwise seems healthy.