specific and Contagious Diseases. 1 5 1 



upon an altered condition of the blood, leading to an 

 asthenic or debility of a peculiarly low type. It may be 

 located at one time in a special set of organs, and during 

 a succeeding attack the manifestations are removed to a 

 totally distant part : thus, at one time it is wholly catarrhal, 

 and in other instances it proves to be either pulmonary, 

 intestinal, hepatic, or cerebro-spinal, all of which may 

 suffer modification in their special characteristics under 

 various circumstances. 



Causes. — Contact with diseased animals is perhaps the 

 chief. The exciting causes are those which by inducing 

 debility, impoverishment of the blood, &c., favour the 

 attack, such as bad or insufficient food, damp, over- 

 crowded, or ill-ventilated dwellings, over-feeding, want 

 of exercise, &c. &c. Worms and teething also contribute 

 their share in reducing the natural stamina of the system. 

 As we are assured of the demonstration of a special 

 disease producing bacterium of micrococcus characters, 

 we may content ourselves in the inevitable assurance of 

 the contagious cause under all circumstances. 



Symptoms. — The most recent views of the nature of 

 this disease are that, primarily, it is a specific form of 

 catarrh, in which the mucous membrane of the air pas- 

 sages, or the upper alimentary track, as far as the stomach, 

 are involved, degenerating, as already stated, into one 

 or other of the forms of pneumonia, hepatic or bilious, 

 enteric or intestinal, and cerebro-spinal or nervous 

 disease. 



The earliest signs of disorder are dulness, lassitude, 

 snuffling or slight husk, or coughing fit, at the close of 

 which the animal attempts to vomit. Somewhat later he 

 is found trembling, with staring coat, a fit of shivers 

 ushering in a subsequent stage. The pulse and tempera- 

 ture are increased, the latter rising to 104° or 105° F. 

 The respiration soon becomes accelerated, and the 

 mucous membranes slightly reddened, which provokes a 

 watery discharge from the eyes and nostrils, and a fre- 

 quent blowing of air from the latter. In a few hours the 

 watery discharges become muco-purulent, or partly 

 mucus and pus, the mouth is hot, and the tongue coated 



