I've had an Isa Brown for three years and she has changed in the past few days. She is no longer eating or laying eggs. She sits in one spot in the yard most of the day with no energy. She appears to be healthy with clear eyes and a clean vent. Is she just depressed or should I look into something else. She get a good diet and clean shelter. I have also tried to check to see if she is egg bound however I don't think that's the problem. Grateful for any advice. Thanks in advance for any suggestions.