Silkie is breathing with mouth open? [vid]

[neverknewnew]

He has not been doing this for long, maybe started this week? But he has been sneezing at times. His droppings seem fine, and I watch him drink and eat and that's all fine and dandy but what is wrong with him? I'm new to raising a Silkie and I'm completely unsure what's the problem. Should I be worried?
I feed him a lot, he's gotten quite big actually, could he just be getting too fat?
Anyway, here's the video of his breathingit's kind of loud and sounds labored)

 

[amillecay]

I'm not sure at first i was going to say maybe he was to hot but you have him inside so that wouldn't be the problem, the one thing you should know though is that chickens don't over eat they once their crop is full they will stop, i even have food out for my chickens at all times. I think you should see what other posts you get on here because i'm not to sure what it is.

 

[amillecay]

Maybe a bit of a cold? do you have any other chickens do they have anything going on at all?

 

[neverknewnew]

I mean, I let him outside once in awhile! What did you have in mind?
Could it be heat? I often try and leave windows open in my room for him to get some cool air if that's the problem.

 

[amillecay]

Hmm it could be at the time you were filming this was it really hot?

 

[amillecay]

Oh also does he have any runny nose at all?

 

[neverknewnew]

It's not that hot in my room, it's actually pretty cool in here right now, I mean, he's just resting on my chest for now.
And no, no runny nose, just some occasional sneezes, and that was way before this happened.
Edit:
May I also add he jumps around a lot? Like from bed to the floor? It's not a far drop however, and plus it just glides toward the floor. Could this contribute to this?

 

[amillecay]

Ok so it's not hot no runny nose and he was sneezing before this happened, hmm i'll have to think on this one.

 

[neverknewnew]

I really appreciate you trying to help. I honestly don't know how this could have happened. And even now that I got up and let him run around he's acting fine! It seems to me(from what I can tell so far) he starts breathing this odd way when he's sitting on me.I'll probably try and take him to a vet tomorrow to see.

 

[amillecay]

Hmm well I wish you luck I really don't know what this is. A lot of times vets don't know what they are doing with chickens (unless they are trained in that area some how or have just learned from experience) so I would make sure that you call in before you go there and ending up stressing him out because you don't want that!