What are the clinical symptoms of chronic intestinal coccidiosis in chickens?

Chronic intestinal coccidiosis in chickens often occurs in older chickens. The comb and wattles of sick chickens are pale, with anemia, appetite gradually disappears, progressive weight loss, feathers are ruffled and dirty; they pass watery thin droppings that contain undigested feed, or pass mushy droppings, and have a strong desire to drink. The sick chickens have weak legs and cannot stand up, and finally die of exhaustion.