DISEASES OF THE IIESPIKATORY PASSAGES 179 



tiou of the luenibranes tliat have formed in tlie mouth, it will 

 be found that when they are removed there is left a raw, 

 granular-appearing surfaee. Upon mieroscopie examination, 

 there may be seen cellular infiltration, witli a destruction of 

 cells of the mucous membrane underlying the diphtheric 

 patch. An examinati(m of the maxillary (suborl)ital) siinis 

 (see Fig. 2, No. 81) will reveal it to be filled with a purulent 

 nuiterial, which is often cheesy in consistency. The wall over 

 this part is very thin and can be easily^ opened w4th a knife. 



A microscopic study of sections of the head, through the 

 infiamed area (the mucous lining of the nasal passage) show^s 

 considerable thickening and an acute inflammation (invasion 

 of pohjmorpJionuclear lenkocytes) ; at times the entire pas- • 

 sage is "plugged" with the mucus. 



On examination of the eye and mucous membrane sur- 

 rounding the anterior portion of the eyeball, 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 mus- 

 cles and their surrounding structures. 



Treatment. — Correct any bad sanitation or hygiene, which 

 may be a predisposing cause. The henhouse should be well 

 ventilated, but should allow no drafts on the birds, and 

 should be kept clean and free from dampness. It should be 

 cleaned and disinfected daily wnth some of the mixtures here- 

 tofore described and recommended for this purpose. If the 

 bird is not a valuable one, kill and cremate it, the body as 

 well as the head. 



General Preventive Measures. — Isolation of all diseased 

 fowls from the flock and the removal and l)urning of all dead 



fowds. 



Cleaning and disinfecting of the houses and yards. The 

 resistance of chickenpox virus to the action of disinfectants 

 makes it imperative to disinfect the houses and yards thor- 

 oughly. 



Quarantining for two weeks of all the new stock and of 

 birds returned from poultry exhibits. 



Careful examination of each fowl occasionally, if the dis- 

 ease is present in the neighborhood. 



Preventive Vaccination. — The immunization of fowds against 

 chickenpox has been practiced by a number of investigators. 



:\redicinal treatment differs, with the location of the lesion. 

 For the ulcers, or diphtheric patches, in the mouth, nothing 

 is better than cauterizing wdth lunar caustic. A solution of 



