124 PRACTICE OF EQUINE MEDICINE. 



The inhalation of irritating gases, as smoke, particles of septic 

 dust, dirty hay, or dirty feed. 



This is rarely met with as a simple disease, it generally being 

 associated with deeper inflammations, as following ulceration of 

 the mucous membrane of the nose, in glanders, or it may be sec- 

 ondary to leucocyttuemia, anasmia, pharyngitis, laryngitis. 



Bacteria acting on the inflamed membrane. 



What is the pathology? 



Two stages are recognized — first, or dry stage, and second 

 or moist stage. 



There is an excessive amount of blood in the mucous mem- 

 brane, which is reddened, thickened, and dry in the beginning; 

 then there is an infiltration into the mucous membrane of the nose, 

 causing a thin, watery discharge, the mucous glands beginning 

 to secrete; the discharge becomes thickened and a sticky mucus 

 after a time, or it may become muco-purulent on account of the 

 desquamation of the cells of the mucous membrane and a gen- 

 eration of new cells. 



What are the symptoms? 



First Stage. — There is a cold in the head, the animal is dull 

 and has an apparent headache, lessened appetite, more or less shiv- 

 ering, followed by fever (the temperature is elevated two, three, 

 or four degrees). 



The membranes being reddened, thickened, and dry, give rise 

 to sneezing. This 6tage lasts from several hours to several days. 



Second Stage. — Following this dry stage, the mucous mem- 

 brane is shiny, much swollen, and cedematous; there is a discharge 

 which at first is thin and watery, but soon becomes thickened and 

 opaque and of a whitish color, due to the white blood-cells; 

 in some cases it may be yellowish; crusts often form around 

 nostrils. 



The mucous membrane of the eyes becomes involved, being 

 dry and reddened at first, but soon a discharge takes place, which 

 at first is thin and watery, and later thick and pus-like. 



What is the duration of an acute case ? 



The milder cases last about a week, while the more severe 

 cases twice that time or longer, depending on the constitution of 

 the animal and the severity of the attack. 



