So sorry you lost Mocha. He was a very, very sick boy. He was far beyond getting any benefit from Safeguard. I strongly recommend you find a lab to do a necropsy on him. Refrigerate his body until then. Or you can also do it yourself. It will be obvious if he has tumors that killed him.
A necropsy from a lab could tell you if your flock has an avian virus that might affect the remaining chickens. This knowledge can be very important to how you manage your flock going forward.
A necropsy from a lab could tell you if your flock has an avian virus that might affect the remaining chickens. This knowledge can be very important to how you manage your flock going forward.