Which of the following symptoms is associated with pathogenic diseases in poultry?

The symptom that is most commonly associated with pathogenic diseases in poultry is diarrhea. Diarrhea is a common sign of infections caused by bacteria, viruses, or parasites that can infect the digestive system of birds. These infections can result in inflammation of the digestive tract, which can lead to watery and loose stools. Other symptoms may also be present, such as lethargy, loss of appetite, and dehydration. Feather pecking and egg eating are behavioral problems that are not necessarily indicative of disease. Rickets, on the other hand, is a nutritional disorder caused by a deficiency of Vitamin D or calcium, and it affects the bones and skeletal system of the bird. Therefore, diarrhea is the most likely symptom to be associated with pathogenic diseases in poultry.