CHAPTER XXI 

 INFLAMMATION AND WOUNDS 



Inflammation is a pathological condition of a tissue, char- 

 acterized by altered function, disturbance of circulation, and 

 destructive and constructive changes in the irritated part. Heat, 

 redness, swelling, pain and disturbed function are the symptoms 

 which characterize inflammation. 



The changes in the circulation occurring in inflammation are 

 as follows : (1) An increase in the rate of the blood-flow through 

 the blood-vessels of the part and their dilation; (2) diminished 

 velocity followed by the blood-flow becoming entirely suspended ; 

 (3) following the retardation or suspension of the blood stream, 

 white blood-corpuscles accumulate along the w'alls of the small 

 veins and capillaries ; (4) white and red blood-corpuscles migrate 

 from the vessels into the neighboring tissue, and blood-serum 

 transudes through the walls of the vessels, forming tlie inflamma- 

 tory swellings. The red blood-cells do not escape from the blood- 

 vessels in any numbers unless the walls of the blood-vessels 

 become injured or badly diseased. 



The causes of inflammation may be grouped under the fol- 

 lowing heads : mechanical, chemical, thermic and infectious. 

 The mechanical or traumatic causes commonly produce in- 

 flammation in domestic animals. These are kicks, strains of 

 tendons, ligaments or muscles and wounds. Inflammation 

 originating from injuries very frequently changes to an in- 

 fectious form, through the infection of the part by bacteria. 

 Bruised tissue may become infected with pus-producing organ- 

 isms, and an abscess or local swelling form. All accidental 

 wounds in domestic animals become more or less infected by 

 irritating microorganisms. 



The following symptoms occur in local inflammation. In- 



203 



