RESPIRATORY & CIRCULATORY SYSTEMS 169 



horse in the latent stages of disease were put on board 

 ship amongst healthy horses, that animal would constitute 

 a centre of infection, with every probabihty of many other 

 horses becoming infected, and these in their turn would 

 become capable of infecting others. Although rigid 

 veterinary inspection took place on embarkation and 

 disembarkation it was practically impossible to avoid an 

 accident of this kind when dealing with thousands of 

 horses. Moreover, administrative inefficiency and the 

 indiscriminate application of knowledge — knowledge of 

 a very limited character — was responsible for the mis- 

 directed energy applied and the consequent high percent- 

 age of deaths amongst horses from this disease, both at 

 home and abroad. 



Sometimes this contagious lung fever of horses occurs 

 in civilian studs, particularly if the ventilation and 

 general sanitary arrangements are defective. Unquestion- 

 ably the disease is due to the presence of micro-organisms 

 in the lungs and blood, and its appearance amongst 

 horses is always the result of infection from a pre-existing 

 case. Previous to the European war it was customary to 

 regard this form of pneumonia as constituting part of the 

 epidemics of influenza ; in fact, the majority of horse 

 owners, in Great Britain at any rate, usually looked upon 

 it as the lung form of that disease. It is very doubtful 

 whether this form of pneumonia should be looked upon or 

 regarded in this light. The method of transmission is, in 

 the writer's opinion, through the ingestion of infected 

 food, and to a less extent by direct inhalation of air 

 infected by the organisms of this disease. The period of 

 incubation is from three to eight days, but usually about 

 the first-named period. In the majority of instances the 

 pathological changes in the lungs and their coverings are 

 of a very acute character and nearly always accompanied 

 by effusion or dropsy of the chest of a very severe nature. 

 Commonly several gallons of fluid are found in the chest 

 after death, and the whole cavity is filled with feebly 



