INFECTIOUS DISEASES OF CATTLE. 381 



mat-ion of the lungs and pleurae, but they vary considerably according 

 To the type which the disease manifests. If the attack is anacuteone, 

 ;is is frequently seen in hot weather, the symptoms appear suddenly, 

 the breathing becomes rapid and difficult, the animal grunts or moans 

 with each expiration, the shoulders stand out from the chest, the head 

 is extended on the neck, the back is arched, the temperature is 104 to 

 107, the milk secretion is suspended, there is no appetite, rumination 

 is stopped, the animal may bloat and later be affected with a severe 

 diarrhea. Such cases are generally fatal in from seven to twenty days. 



Very often the attack comes on slowly and the symptoms are much 

 less clear. In the mildest cases there is a cough for a week or two, but 

 no appreciable loss of appetite or elevation of temperature. The lungs 

 are but slightly affected and recovery soon follows. Such animals may 

 disseminate the contagion for a long time without being suspected, and 

 lor that reason are the most dangerous of all. 



A more severe type of the plague is the most frequently seen. In 

 these cases the cough is frequent, more or less painful, the back some- 

 what arched, and the milk secretion diminished. The prominence of 

 these symptoms increases, the appetite is affected, the animal loses flesh, 

 the breathing becomes more rapid, the cough more painful, pressure of 

 the fingers between the ribs shows tenderness, the hair loses its gloss 

 and stands erect, the skin becomes adherent, little if any milk is secreted, 

 and the temperature rises to 103 or 105. Animals thus affected may 

 continue to grow worse and die in from three to eight weeks, or they 

 may after a time begin to improve and make an apparent recovery. 

 The inflammation of the lung does not, as a rule, subside and the organ 

 return to its normal condition as is the case in ordinary pneumonia, but 

 with this disease the life of the affected portion of the lung is destroyed, 

 the tissue dies and a fibrous wall is formed around it to shut it away 

 from the living parts of the body. The tissue, thus encysted, gradu- 

 ally softens, becomes disintegrated and breaks down into pus. The 

 recovery, therefore, is not complete; it is only apparent and partial. 



To tho.se accustomed to examining the lungs of cattle, other and 

 extremely important symptoms may be detected during the course of 

 the disease. By applying the ear over the walls of the chest an area 

 of a certain extent may be found where the natural breathing sound is 

 diminished or entirely lost. This represents the diseased portion of the 

 lungs. In other cases a loud blowing sound may be heard, quite dif- 

 ferent from any sound produced when the lung is in a healthy con- 

 dition. In some cases crepitation is heard near the border line of the 

 diseased area, and friction sounds produced by the roughened pleura; 

 but these can only be appreciated by those whose ears have been 

 trained to distinguish between the different sounds which reach the 

 ear when applied to the chest wall. By pemission, that is, by pressing 

 the fingers of the left hand (irmly against the wall of the chest and tup- 

 ping UIKIII the middle finger with the ends of the fingers of the right 



