RESPIRATORY DISEASES 153 



the rapid emaciation of tlie bird following a se- 

 vere attack, shows. Upon examination of the 

 membranes that have formed in the mouth, it will 

 be found that when they are removed there is 

 left a raw, granular appearing surface. Upon 

 microscopic examination, cellular infiltration is 

 seen, with a destruction of cells of the mucous 

 membrane underlying the diptheric patch. An ex- 

 amination of the maxillary (suborbital) sinus (see 

 Plate I, No. 31) will reveal it to be filled with a 

 purulent material, which is often cheesy-like in 

 consistency. The wall over this part is very thin 

 and can be easily opened with a knife. 



A microscopic study of sections of the head, 

 through the inflamed area (the mucous lining of 

 the nasal passage) shows considerable thickening 

 and an acute inflammation (invasion of polymor- 

 phonuclear leukocytes); at times the entire pas- 

 sage is "plugged" with the mucus. 



On examination of the eye and mucous mem- 

 brane surrounding the anterior portion of the eye- 

 ball, there may be seen a cloudy condition of the 

 cornea, the anterior portion of the ball (keratitis) . 

 There is also an acute inflammation of the mucous 

 membrane of the eye (acute conjunctivitis). 



In cases studied in this laboratory it has been 

 found that the acute inflammation extends to the 

 iris and ciliary muscles and their surrounding 

 structures. 



Treatment. — Correct any bad sanitation or hy- 

 giene, which may be a predisposing cause. The 

 henhouse should be well ventilated, but should al- 

 low no draughts on the birds, and should be kept 

 clean and free from dampness. It should be 

 cleaned and disinfected daily with some of the 

 mixtures heretofore described and recommended 



