104 GENERAL THERAPEUTICS FOR VETERINARIANS 



The automatic respiratory centre in the medulla oblongata can 

 be stimulated directly and indirectly by different stimuli, espe- 

 cially drugs. Insufficient oxygen and excess of carbon dioxide in 

 the blood (anaemia, venous hyperaemia, muscular activity), febrile 

 temperature, and atropine, scopolamine and other drugs act as 

 direct stimulants. Indirectly, or reflexly, the respiratory centre is 

 stimulated by stimulation of the peripheral ends of the vagus nerve 

 (regulating nerve of respiration) in the lungs, the cutaneous sensory 

 nerves (painful trauma, inflammation, cold), the superior laryngeal 

 nerve (cough), the trigeminal, olfactory and other peripheral 

 nerves. The artificial stimulation of the respiratory centre is very 

 important, for example, in chloroform asphyxia (atropine, scopo- 

 lamine, slapping the skin in the region of the flanks, cold douches). 



Therapeutic Methods. — 1. In the treatment of diseases of the 

 organs of respiration, the most important therapeutic measure is a 

 provision for a supply of pure air. Good ventilation of the stable 

 or, when possible, keeping the patient in the open air (pasturing, 

 bivouac, staking) is alone sufficient to effect a cure in many cases. 

 This is especially true of the catarrhal and infectious diseases of 

 the organs of the chest. Experience in the Prussian army has in 

 numerous instances shown the favorable effects of bivouacking in 

 summer, particularly in contagious pneumonia in horses. Moist 

 air (warm winds) is also very healing in catarrhs of the respiratory 

 mucous membrane; it promotes the liquefaction of the catarrhal 

 secretions. In contrast with this is the drying and heat-extracting 

 influence of cold winds. With the air therapy should be combined 

 proper care of the skin (cutaneous respiration). 



2. Drugs may be employed for different purposes. Of special 

 consideration are the so-called expectorants, i.e., drugs which 

 promote the throwing off, or expectoration, of abnormal sub- 

 stances from the respiratory tract (see p. 107). Also of importance 

 are the derivative (cathartics, diuretics and sialagogues) and the 

 symptomatic methods (narcotic cough remedies) of treatment, 

 the use of stimulants to the respiratory centre, and the astringent, 

 antiseptic and antiparasitic methods (catarrhs, infectious dis- 

 eases, lung worm epidemics). 



