DISEASES OF THE RESPIRATORY ORGANS 497 



animal there is more ventilating surface with equal cubic space, and partly 

 because the air permeates the walls more readily. 



DISEASES OF THE KESPIRATORY OKGANS 

 CATARRH OR COLD 



Definition. The term catarrh is generally used to describe an inflam- 

 matory condition of the lining membrane of the upper portion of the air- 

 passages, commonly spoken of as "a cold", the special feature of which is a 

 discharge of varied character from the nostrils, and sometimes the eyes also. 



Causes. The popular term cold, or a cold correctly points to the 

 origin of many cases of this disorder, but it should be understood that 

 there are other causes of catarrh with which cold has no concern. For 

 the most part it results from lengthened exposure to inclement weather 

 under conditions of exhaustion and inadequate food, sudden change from 

 an overheated and usually badly ventilated stable to the outer cold, and 

 it is the general experience among horsemen that the opposite conditions 

 to the latter frequently cause it. It would seem paradoxical that an 

 animal should take cold on coming from a cold atmosphere to a warm one, 

 and from nakedness to clothing and comforts. The explanation is probably 

 to be found in the unwholesome and irritating nature of the stable atmos- 

 phere upon the sensitive membranes of the air-passages. A horse requires 

 a very large amount of air space, and the inadequate amount usually 

 allowed is only tolerated when he has become acclimatized to close quarters. 

 The advantages of pure air as a curative agent, when catarrh is established, 

 are so well recognized among horse-dealers that some adopt the heroic 

 though imprudent course of turning them out in a field. When the skin 

 of a weak perspiring horse is suddenly exposed to a cold wind, the surface 

 circulation receives a check of which the cold is a reaction or local mani- 

 festation. The animal's condition at the time of exposure would appear 

 to have much to do with his susceptibility in this respect; indifferent 

 health and fatigue are unquestionably predisposing conditions. The horse 

 in hard condition, sweating but not exhausted, will bear a cold shower- 

 bath without taking cold, but his vital powers are sufficiently great to 

 produce a healthy reaction. 



Infection. An infectious form of catarrh is now generally recognized, 

 and as such the disease periodically visits most large establishments where 

 a great number of horses are stabled. Young horses, fresh from the 

 country and drafted into town studs, seldom escape an attack, but their 

 susceptibility to further infection would appear to be materially reduced 

 as a consequence. 



