486 DISEASES OF THE HORSE. 



of arresting hemorrhage, since it disturbs healing least and gives the 

 gi-eatest security against secondary hemorrhage. 



SUTURES. 



After the bleeding has been controlled and all foreign bodies 

 removed from the wound, the gaping of the woimd is noticeable. It 

 is caused by the contraction of the muscles and elastic fibers, and its 

 degree depends on the extent, direction, and nature of the cut. This 

 gaping will hinder the healing process so that it must be overcome by 

 bringing the edges together by some sort of sutures or pins or by a 

 bandage applied from below upward. As suture material, ordinary 

 cotton thread is good, if well sterilized, as are also horsehair, catgut, 

 silk, and various kinds of wire. If the suture is made too tight the 

 subsequent swelling may cause the stitch to tear out. In order to 

 make a firm suture the depth of the stitch should be the same as 

 the distance the stitch is from the edge of the wound. The deeper 

 the suture the more tissue is embraced and the fewer the number of 

 stitches required. In tying a suture the square or reef knot should 

 be used. Closure of wounds by means of adhesive plaster, collodion, 

 and metal clamps is not practiced to any great extent in veterinary 

 practice. 



PROCESS OF HEALING. 



In those cases where perfect stoppage of bleeding, perfect coapta- 

 tion of the edges of the wound, and perfect cleanliness are obtained, 

 healing occurs within three days, without the formation of gi-aula- 

 tions, pus, or proud flesh, by what is termed first intention. If 

 wounds do not heal in this manner they will gap somewhat and 

 become warm and painful. Healing then occurs by granulation or 

 suppuration, which is termed healing by second intention. The 

 sides of the wound become covered with granulation tissue which 

 may fill the wound and sometimes overlap the lips, forming a fungoid 

 growth called proud flesh. Under favorable conditions the edges of 

 the wound appear to grow together by the end of the first week, and 

 the whole surface gradually becomes dry, and finally covered with 

 pigmented skin, when the wound is healed. The cause of pus forma- 

 tion in wounds is usuall}^ the presence of germs. For this reason the 

 utmost care should be adopted to keep clean wounds aseptic, or free 

 from germs, and to make unclean wounds antiseptic by using anti- 

 septic fluids to kill the microbes present in the wound. The less the 

 injurious action of this fluid on the wound and the greater its power 

 to kill germs, the more valuable it becomes. All antiseptics are not 

 equalh^ destructive, and some germs are more susceptible to one 

 antiseptic than to another. The most important are (1) bichlorid 

 of mercury, which is to be preferred on horses. It becomes weakened 



