SECRETARY'S REPORT. 47 



7. It is not certain that tliose who take care of affected 

 animals can communicate the disease to those which are healthy. 



8. The purchase of affected animals, at fairs, markets or 

 elsewhere, in localities where the disease prevails, is a great 

 cause of its dissemination. 



9. Twenty-six veterinary surgeons of high standing in France, 

 Germany, Italy, Switzerland, Belgium and Holland, have pub- 

 lished their opinion, in favor of the contagiousness of the dis- 

 ease ; and in the veterinary congress held at Hanover in 1841, 

 all the members, twenty-three in number, declared their belief 

 in the same. 



10. The time of incubation is from twenty-four to twenty- 

 five days, but, as it is difficult to settle precisely the moment 

 of contagion, we must admit that the time is from thirty to 

 forty days, more often within, very rarely beyond this. 



11. The nature of the virus, like that of all contagious dis- 

 eases, is still unknown. Its seat appears to be the affected 

 lung. The expired air, the nasal mucus, the saliva, the 

 emanations from the affected organs are the ordinary vehicles. 

 Finally, the contagious atmosphere around the animals is 

 limited, and cannot be carried far by currents of air. 



Admitting then that such a disease as contagious pleuro- 

 pneumonia exists, let us endeavor to ascertain whether there 

 are any symptoms by which it may be recognized. 



Dr. J. M. Kreutzer, in a valuable work upon this subject, 

 published at Erlangen in 1854, gives the following : — 



The most unmistakable signs of pulmonary disease are 

 derived from auscultation and percussion, but it is impossible 

 by these means to discover the nature of the lesion ; we cannot 

 distinguish it from simple inflammation of the lungs. 



Among the external sigus, we have almost always a peculiar 

 short cough, particularly in the morning, or when the animal 

 rises or is allowed to drink. The appetite is variable or slight, 

 the secretion of milk diminished. At a later period there is 

 unusual dilatation and contraction of the ala3 nasi, and a more 

 or less rapid, short and unequal respiration. The peculiar 

 cough becomes more dry and painful, and, in the very worst 

 cases may be entirely absent. In young, powerful animals, the 

 mucous membrane of the nose is, at the commencement, red 

 and dry, but, at a later period the color changes to a yellowish- 



