My pet chicken, Ruby, has lost SO much wieght in the last 3 weeks. She use to be really really heavy , now she is lighter than my runt of the flock who is only 10 months old. Ruby is 14-15 months old. She hasn't been active much at all, just plotting around slowly and always is slow to come when called. She is eating normally and not getting picked on. She doesn't have any visible mites or lice. I don't know what to do!?!? She is my baby! Please help and tell me all you know!she really isn't well!