Concerned about my 2 week old Pekin

[112runners]

I have 2 Runners and 2 Pekins and they are a day over 2 weeks old. Im keeping them in my garage in a plastic kiddie pool with hay, they have plenty of access to food and water and the heat lamp is emitting a steady 88 degrees.

Tonight I noticed something strange about one of my Pekins. He (or She) seems to be breathing heavy and is opening up its beak and appearing to 'heave'. I am afraid it is choking, although it is eating and drinking just fine and still emits a 'distress call' when it is separated from its pals.

Should I be concerned? Is he just trying to quack?

TYA

Edit: I allowed them to play in the grass for about an hour today and they appeared to be eating some grass and dirt. Do I maybe need to provide him some grit?

 

[Habibs Hens]

is there ventilation in your garage

i lost a whole batch of 22 chicks once as there was no vents and the air was stagnant and they became breathless from the stagnant air

 

[Amiga]

Any chance the hay is getting damp and moldy? Ventilation is a good thing to think about.