disp:ases ok poultry. 



33 



willi the orbital s])ace or ca\-il\- surrouiuliiij^ the ej'es. 

 The orl)ital space in birds is relatively very large and 

 has an angular projection towards the point of the beak. 

 There is, consequentl}', considerable sjiace between the 

 ej'e -ball and the bon}- walls surrounding it, which is 

 known as the orl)ital space or orbital sinus. This 

 space is lined with a mucous membrane which is con- 

 tinuous with that of the nostrils and in such close rela- 

 tions with it that an inflammatory process readily ex- 

 tends from one to the other. Very often in roup, this 

 membrane is inflamed throughout these passages, and 

 the ])rocess is so acute that the surface ])ecomes eroded 

 and ulcerated. The secretion, instead of remaining 



fluid as in simple ca - 

 tarrh, changes at this 

 period, is abundant, 

 thick, yellowish pu- 

 rulent, and cheesy. 

 This secretion ac- 

 cumulate s and ob - 

 structs the ])assages. 

 It forms around the 

 eye and forces the 

 eye -ball out of the 

 socket and at the 

 same time collects 

 under the ej-elids or 

 on the corner, some- 

 times simulating a 

 false membrane. It, also, plugs the nasal passages, 

 presses down the palate, obstructs the breathing and 

 may prevent swallowing. 



The affected 1)irds in the advanced stages of the 

 disease present a most miserable apiK'arence. The 





^^fwmm 



Fif,'. 2.— Head of bird .iffpcted with 

 contagious catarrh. 



TJNTVFRSTTY 



•^ 



