Breathing with mouth open, resulting in death.

[darkbrahmamama]

I had a 2 year old dark brahma hen die over night. Yesterday I noticed her sitting on a roosting bar with her eyes closed. When I put her in her own stall, she was breathing through her mouth while standing. No coughing, no wheezing, no nasal discharge, eyes were clear & not running, comb & wattles were still very colorful, no swelling in the face. She was fine Saturday, but someone else does chores on Sunday, so I don't know how she was acting then. I just got done deworming everyone with liquid safeguard for goats about 2 weeks ago. My chickens completely free range during the day, & it has been extremely wet here in NEPA. Could she have possibly ate or drank something bad? It's just a few days after I lost a year old hen that has had multiple laying issues since she started laying ..... not a good 2015!