ACUTE CATARRH. 457 



inadequate feeding and bad treatment ; (3) Previous attacks 

 of the same affection witliin a limited period. 



Of the direct inducing factors the more appreciable are — 

 (1) Exposure to cold and moisture, particularly when pre- 

 viously heated ; (2) Contact by cohabitation with animals 

 suffering from the same disturbance. 



1. Exposure to the Vicissitudes of Weather. — This, as well 

 as placing animals in damp stables, or any sudden lowering of 

 the surrounding temperature, has ever, with the most of 

 observers, been considered as the most fruitful cause of colds. 

 It does not, however, appear that mere cold, or exposure to 

 cold, is so apt to induce this condition as some have imagined. 

 I am well aware of the fact that a fall of temperature ex- 

 tending to 10° or 20° F. will in a wonderfully short period 

 develop a large number of cases of catarrh amongst horses in 

 any city; this, however, of itself will not account for these 

 results. In those cases, animals so circumstanced are, from 

 the unnatural condition of location in overheated, imperfectly 

 ventilated lodgings, so enervated and weakened, that the in- 

 fluence of a lowered temperature suddenly applied acts detri- 

 mentally upon them. 



Sudden variations of temperature do not, in animals favour- 

 ably circumstanced, seem very apt to induce disease. Witness 

 the use of the Roman, misnamed the Turkish, bath, where a 

 cold douche is given after leaving the sudatorium. The appli- 

 cation of cold seems chiefly to be dangerous when apphed to 

 the previously heated body, exhausted by exercise or fatigue, 

 slowly parting with its- heat; so that there seems strong reason 

 for believing that the influence of change of temperature and 

 exposure to damp are chiefly to be feared when the animal 

 body is exhausted by fatigue or exposure to debilitating in- 

 fluences. 



In some old writings on veterinary matters we find catarrh 

 attributed to obstructed perspiration. To this some of our 

 modern authors have taken objections. However, cogent 

 reasons may be adduced in support of the supposition that the 

 symptoms exhibited in ordinary catarrh are dependent on the 

 presence in the blood of a specific animal poison, which, either by 

 its direct presence there, or its special irritation of these organs 

 and structures which naturally are its intended emunctorics, is 



