80 INFLUENZA. 



the drinking water carbonate of soda, or placing clialk in tlie 

 manger, changing the diet and exhibiting mild vegetable 

 tonics. These latter, when not producing the desired effect, 

 ought to be changed or alternated with others, as sulphate of 

 iron or liquor arsenicalis. The latter is a good tonic, and 

 readily taken in the food or drinking water. 



Sequelae. — Although the larger percentage of the cases of 

 influenza terminate favourably, and leave no permanent 

 functional disturbance or structural change, all are not thus 

 clear of obnoxious and damaging sequeloe. 



The untoward and damaging results which follow an attack 

 of influenza in the horse are chiefly encountered in connection 

 with the principal organ of circulation — the heart, and with 

 these of respiration, the lungs and air tubes, great and small, 

 or with the tendons and sheaths of the great flexor muscles of 

 the limbs. In a less number we have changes in connection 

 with the great nerve-centres ; these, however, are more likely to 

 develop themselves chiring the height of the fever than after 

 its defervescence. 



The changes which thus result from the diseased action in 

 the upper portion of the air-tube and in the region of the 

 larynx are the most common, and tend, by their interference 

 with the free passage of air to and from the lungs, to produce 

 varying abnormal sounds. The structural changes thus 

 resulting in defective performance of function are various, as 

 thickening of laryngeal lining membrane, enlargements in 

 connection with the vocal cords, disease of muscular structures 

 connected with the sections or cartilages of the larynx whereby 

 these cartilages are imperfectly maintained in their natural 

 position and relation to each other, thereby altering the calibre 

 and form of the entrance to the great air-tube. 



In the lower air-passages, the smaller air-tubes and air-cells, 

 the defective functional activity incident to change of struc- 

 ture is less marked, unless the horse is caused to make rapid 

 exertion, when the deficient puhnonic aerating surface wiU 

 most probably induce some amount of dyspnoea or embar- 

 rassment in breathing. 



When the heart and its ai)pendages are the seats of change 

 incident to previous disease, the consequences are much more 

 serious than where the respiratory organs proper are involved. 



