Diseases of the Respiratory Organs. 43 



Predisposing Causes. — Hereditary disease, as scrofula or 

 phthisis, an anaemic or plethoric habit of body, sudden and 

 frequent changes of temperature. 

 ^^ Exciting Causes. — Exposure to cold and damp (especially 

 in toy or house-dogs, frequently washed and not carefully 

 dried, and who are used to a warm atmosphere), violent 

 exertion, penetrating lung wounds. 



Symptoms. — The stages of pneumonia are usually three : 

 1st, that of engorgement, or congestion ; 2nd, red hepatiz- 

 ation ; 3rd, yellow or grey hepatization, or purulent infil- 

 tration. 



The early stage is generally ushered in with shiverings, 

 followed by fever ; the pulse is increased, the respiration 

 becomes quickened, there is an occasional short cough, the 

 head is extended, the eyes bloodshot, nose hot and dry, 

 tongue protruded and furred, edges of a deep red ; the 

 animal assumes a sitting posture, with the fore-legs wide 

 apart. 



Ausculation reveals a crackling or crepitating sound, 

 which is circumscribed according to the amount of lung 

 , involved ; this sound obscures to a great extent the respir- 

 atory murmur in those portions not diseased, and as the 

 malady proceeds this murmur becomes quite obliterated, the 

 crepitus general and more defined, and the other symptoms 

 all increased in severity. 



If the malady is not checked at this stage, it quickly 

 passes on into the second. The crepitus on auscultation is 

 absent, and no sound, except it be a slight wheezing or 

 whistling noise, can be detected ; hepatization has then taken 

 place, and inflation is but a cypher. The sound emitted on 

 percussion at this stage is very characteristic of consolidation 

 being flat and dead. 



The cough now is, frequent, and accompanied with red or 

 rusty expectoration ; the eyes have a sunken appearance ; 

 respiration is performed with great effort and pain ; the 

 cheeks are inflated in the act, nostrils dilated, and the 



