DISEASES OF THE AIR PASSAGES. 



The air passages are the nostrils, the larynx, the wind- 

 pipe and its ramifications, and the bronchial tubes. The 

 horse, on account of the great size of the soft palate, can- 

 not breathe through its mouth. The chambers of the nose 

 are therefore exposed to noxious effluvias in the air, while 

 the mouth is exempt. This difference from man in struc- 

 ture and economy probably accounts for the proneness of 

 the horse to pulmonary affections. The nasal membrane 

 should be frequently inspected. In health it displays a 

 dotted, shining, humid aspect, of a more or less flesh 

 color. Mucus is a sign of disease. 



CATARRH, 



An unhealthy discharge from the nose, in the membrane 

 of which it has its seat, is usually if not invariably the 

 result of cold — that is, cold that causes unusual suffering. 

 Percivall says that catarrh is much oftener the result of 

 transition from cold to heat than from heat to cold ; also 

 that horses kept in the open air altogether are hardly 

 susceptible to catarrh. 



The disease is peculiar to young horses and is sometimes 

 epizootic. It is common, but it is usually harmless. How- 

 ever, it should not be neglected, for it may lead to bron- 

 chitis, nasal gleet, roaring, &c. 



Simple and Febrile Symptoms.— Sneezing; redness 

 and dryness of nasal membrane ; watery, irritating dis- 

 charge, becoming in a few days turbid, yellowish, and 

 irregular ; redness of conjunctival (eye) membrane ; copi- 

 ous tears; hanging head; yawning; heat and pain over 



