370 DISEASES OF CATTLE. 



the temperature is 104° to 107° F., 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 7 to 20 days. 



Yery 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 for 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 

 somewhat arched, and the milk secretion diminished. The promi- 

 nence of these symptoms increases, the appetite is affected, the ani- 

 mal 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, varying in differ- 

 ent animals from 103° to 107° F. Animals thus affected may con- 

 tinue 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 dise&se 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. 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 those accustomed to examining the lungs of cattle, other and 

 extremely important symptoms may be apparent 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 in which the natural breathing 

 sound is diminished or entirely lost. This represents the diseased 

 portion of the lungs. In other cases a loud blowing sound ma}' be 

 heard, quite different from any sound produced when the lung is in 

 a healthy condition. In some cases crepitation is heard near the 

 border line of the diseased area and friction sounds produced by the 

 roughened pleura ; these can be appreciated, however, only by those 

 whose ears have been trained to distinguish between the different 

 sounds which reach the ear when applied to the chest wall. By per- 

 cussion — that is, by pressing the fingers of the left hand firmly against 

 the wall of the chest and tapping uj^on the middle finger with the 

 ends of the fingers of the right hand — an area of dullness may be 

 discovered corresponding to the portion from which the respiratory 

 murmur has disappeared. This loss of respiration detected by auscul- 



