152 HORSE, SWINE AND POULTRY DISEASES 



gestion, or engorgement, of the blood vessels, followed by leakage of 

 serum containing fibrin from the blood vessels into the air passages. 

 The fluids thus escaping into the air cells and in the minute 

 branches of the little bronchial tubes become coagulated. 



The pleura covering the affected parts may be more or less in- 

 flamed. A continuance of the foregoing phenomena is marked by 

 a further escape of the constituents of the blood, and a change in 

 the membrane of the cells, which become swollen. The exudate that 

 fills the air cells and minute bronchial branches undergoes disinte- 

 gration and softening when healing commences. 



The favorable termination of pneumonia is in resolution, that 

 is, a restoration to health. This is gradually brought about by the 

 exuded material contained in the air cells and lung tissues becoming 

 broken down and softened and absorbed or expectorated through 

 the nostrils. The blood vessels return to their natural state, and the 

 blood circulates in them as before. In the cases that do not termi- 

 nate so happily the lung may become mortified, or an abscess may 

 form, or the disease may be merged into the chronic variety. 



Pneumonia may be directly induced by any of the influences 

 named as general causes for diseases of the organs of respiration, 

 but in many instances it is due to neglect. A common cold or sore 

 throat may be followed by pneumonia if neglected or improperly 

 treated. An animal may be debilitated by a cold, and when in this 

 weakened state may be compelled to undergo exertion beyond his 

 strength ; or he may be kept in bad quarters, such as a badly venti- 

 lated stable, where the foul gases are shut in and the pure air is shut 

 out; or the stable may be so open that parts of the body are exposed 

 to drafts of cold air. An animal is predisposed to pneumonia when 

 debilitated by any constitutional disease, and especially during con- 

 valescence if exposed to any of the exciting causes. Foreign bodies, 

 such as food, accidentally getting in the lungs by way of the wind- 

 pipe, as well as the inhalation of irritating gases and smoke, ofttimes 

 produce fatal attacks of inflammation of the lungs and bronchial 

 tubes. Pneumonia is frequently seen in connection with other dis- 

 eases, such as influenza, purpura hemorrhagica, strangles, glanders, 

 etc. Pneumonia and pleurisy are most common during cold, damp 

 weather, and especially during the prevalence of the cold north and 

 northeasterly winds. Wounds puncturing the thoracic cavity may 

 cause pneumonia. 



Symptoms. Pneumonia, when a primary disease, is ushered 

 in by a chill, more or less prolonged, which in many cases is seen 

 neither by the owner nor the attendant, but is overlooked. The 

 breathing becomes accelerated, and the animal hangs its head and 

 has a very dull appearance. The mouth is hot and has a sticky feel- 

 ing to the touch; the heat conveyed to the finger in the mouth 

 demonstrates a fever; if. the thermometer is placed in the rectum the 

 temperature will be found to have risen to 103 F. or higher. The 

 pulse is frequent, beating from fifty or sixty to eighty or more a 

 minute. There is usually a dry cough from the beginning, which, 

 however, changes in character as the disease advances ; for instance, 



