596 ACUTE INFECTIOUS DISEASES 



the skin is thickest, but on the wattles and feathered skin 

 around the head this feature is less pronounced. Masses 

 of tough yellow material often distend the suborbital fossae, 

 accumulate in the external ear, in the lung substance and 

 along the digestive tract. 



Symptoms.— The disease assumes various forms, depend- 

 ing upon whether it involves the mucous membranes of 

 the mouth, the nasal passages, the eyes, the intestinal tract, 

 or the skin. It is necessary from a clinical standpoint to 

 consider these various types of the disease. It is this fact 

 which has led to so much confusion among the poultrymen, 

 as they have been inclined to consider these forms separate 

 diseases. 



Nasal Passages.— The early symptoms are similar to those 

 of an acute nasal catarrh, but the bird shows more dulness 

 and prostration and there is present a peculiar offensive 

 odor. The odor is very characteristic. The discharge 

 from the nasal passages is at first thin, serous and later 

 becomes thicker and glutinous, causing the affected birds 

 to sneeze and shake their heads in an effort to clear the 

 nasal passages. The nasal secretions collect around the 

 openings, forming dirty, yellowish crusts. The infra-orbital 

 fossae become inflamed and distended with pus, forming 

 an enlargement on one or both sides of the head below the 

 eyes. Owing to the occlusion of the nasal passages the bird 

 breathes with open mouth. 



Eyes.— At first a thin serous secretion is observed flowing 

 from one or both eyes; later it becomes turbid, thicker, 

 adheres to the edges of the eyelids and dries to form crusts 

 completely closing the eye. The retained yellow material 

 becomes thicker and often accumulates to such an extent 

 that it causes a pronounced bulging of the eyelids. Masses 

 of this material as large as a walnut are often removed from 

 beneath the lids. Sometimes infection develops posteriorly 

 to the eyes in the form of abscesses which force the eyes 

 partly out of position. The -cornea is turbid and often 

 ulcerated. Complete destruction of one or both eyes is 

 often observed in severe cases. 



