486 DIPHTHERIA IN FOWLS 
introduced the disease spread rapidly. Dampness and lack of ventila- 
tion no doubt favor the maintenance of the virus when introduced. 
Experiments with exudates from affected fowls have been successful 
in some cases. The positive results seem jto have been where the 
epithelial nodules were present. 
Symptoms. There is a watery secretion from the nostrils and often 
from the eyes, with general weakness and prostration greater than 
would be expected from simple catarrh. The birds sit with the back 
arched, the head and neck drawn towards the body, the plumage 
roughened, respirations rapid and audible, vision impaired, and 
difficult swallowing. There is frequent shaking of the head, sneezing 
Fig. 111. FOWL SHOWING THE SUBORBITAL SINUS DISTENDED. THE EYE IS PARTIALLY 
CLOSED. 
and expulsion of mucous secretions. At this early period the tongue 
is pale, while small grayish spots, shaded with black and slightly 
projecting above the surface, may be seen along the border, the upper 
surface or at the base. 
The following day the condition is aggravated, the temperature is 
several degrees above normal, the appetite has disappeared and there 
is diarrhea with greenish or yellowish evacuations. From the open 
beak there escapes a thick, stringy, grayish mucus. The eyes project 
and possibly the conjunctiva may be covered with a thick exudate 
which has accumulated between the lids. The nostrils are obstructed 
by the thickened and dried exudate. Walking is irregular and diffi- 
