I agree testing would be a great idea if I didn't have a 6 year old saying we need to bury it right away and have a chicken funeral for ms. red. Any how I really feel the strain of the egg and the heat are doing them in its the only thing that makes sense and what silkiechicken said about...
I have (had) four chickens and about 2 months ago one of my hens was found in the coup and she seems paralized unable to stand I brought her in the house thinking she just needed to cool down _ I live in arizona it was 110 I forced her to drink some chicken gatoraid and gave her some oatmeal...