My big drake (9 weeks) seems to pant a lot. Way more then the other ducks, even on days that are not that hot. This has been going on for weeks. Thoughts? He eats/drinks/swims and acts just fine and growing like a weed. He is my biggest duck by far.
Check to see if there's anything stuck in his nares. He may need a little extra attention to encourage him to snoot water through them and get the stuff unstuck.
Also, ducks pant when they are nervous, as well.
And it could be an indication he's not feeling well . . . is his breathing at all unusual? Clicking, whistling noises?
Some of these things are just mysterious. My inner duck-hypochondriac is concerned about very early sign of respiratory infection. But that is worst case. Still, I will lay it out there. Not to panic, just to be aware and to watch.