470 HEALTH AND DISEASE 



diminish the output of mucus. Warm applications to the skin, and such 

 drugs as opium, ether, chloroform, belladonna, and hyoscyamus, have this 

 effect. 



While remedies employed in the treatment of diseases of the air- 

 passages and lungs are broadly divided into stimulants and sedatives or 

 depressants, there are some which act in both ways. 



REMEDIES WHICH STIMULATE THE LUNGS AND 

 AIR-PASSAGES 



Enough has already been said to show that all remedies which act as 

 stimulants or tonics to the heart will strengthen the circulation of blood 

 through the lungs. The symptom which most clearly points to the use 

 of a lung or heart stimulant is a blue or purplish colour of the visible 

 membranes, particularly the schneiderian. 



In the acute stage of congestion of the lungs, when an indifferently- 

 conditioned hunter is overtaxed, this blueness is very marked, and a 

 judicious stimulant from the rider's flask may avert a dangerous illness. 

 Ammonia, either given as a draught in water or inhaled, is one of the 

 most effectual lung stimulants. The drugs elsewhere described as car- 

 minative have a quickening effect upon the circulation of blood in the 

 lungs, and the stream appears to flow more freely as a result of such agents 

 as unload the liver and bowels; very marked improvement often follows 

 the administration of small doses of aloes and calomel, which in some 

 indirect way have been proved by trainers to increase the respiratory 

 power of the animals entrusted to them. 



Expectorants may act, as previously suggested, by increasing the j^ower 

 of secretion and quantity of mucus, by loosening the too tenacious and 

 insufficiently fluid matter, or by adding mechanical force to expel the 

 accumulated material. There are coughs in which the animal is " too 

 sore to cough " ; a great desire exists, but the animal dares not yield 

 to it because of the greater pain resulting. An expectorant which alters 

 the character of the spit may make it possible, with much less effort, to 

 set rid of the cause of irritation. In the treatment of horses we are 

 somewhat restricted; we may not give an emetic, which is found in the 

 dog to expel mechanically accumulated material in the bronchi. The 

 relief thus obtained in so-called " stomach " coughs does not necessarily 

 point to that viscus as the seat of disease, but rather gives proof 

 of mechanical assistance afforded in the pressure forward of bronchial 

 mucus, when, by the act of vomition the diaphragm is pressed against 

 the lungs. While, as we have already indicated, expectorants act in a 



