From what I've gathered, my gelding has a cold. He's lethargic on his own, has a runny (clear) nose, dripping eyes, and is a bit grumpy. I'm keeping a temperature drop in consideration, but he's still grumpier than normal. He does not buck or put up a fight when I ask something from him and he's been enjoying his trail rides quite a bit. The laziness/dripping eyes concerns me. He doesn't kick or bite at his body as if he's in pain, but he's an Appy and I've never known an Appy to show weakness.
A little background. He free-ranges on pasture grass alone in a herd of 12 geldings. He's in the middle of the pecking order, though he's not really one to be herd-bound. He's quite fat (I prefer "easy keeper") but not out of shape. I ride him 2 or 3 times a week, though not terrifically hard. I'm more likely to take him out on a 2-hour trail ride than work on canter collection for half an hour. He's been wormed consistently and I haven't noticed anything else unusual. His manure was a bit loose when I first turned him out, but now his digestive system seems to be handling itself.
Anyone experience something similar? Have a diagnosis/recommendations?