I am almost to the point of they are chickens. Sometimes they just get sick. We would all need to live in bubbles to not spread diseases from clothing, shoes, hair, whatever. If one gets sick and dies, just try to fix the problem, learn from it, and try to take steps to not let it happen again. Just my two cents.
Theron, you and Daron are in business of selling chickens to backyard farmers. When we buy from you we want to know that we are not buying chickens who will bring MG or Coccidia to our flocks. Because those two diseases in particular are almost impossible to get off your farm/yard.
Some of us who have had to put down our flocks because of illness are warned, but a new backyard farmer may not know to ask if the chickens he/she is buying are healthy or carrying disease like MG or Coccidia. MG and Coccidia will eventually kill your chickens. Because the chickens over time will develop complications from those chronic diseases.
When I buy chickens again, I will only buy from someone who tests their chickens and can sell me healthy birds.