WOUNDS AND THEIR TREATMENT. 461 



since it disturbs healing least and gives the greatest security against 

 secondary hemorrhasre. 



After the bleeding has been controlled and all foreign bodies 

 removed from the wound, the gaping of the wound 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 is 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 use the square or reef knot. 

 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 granula- 

 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 overlaj^ 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 formation in wounds is usually 

 due to 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 antiseptic 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 equally destructive, and 

 some germs are more susceptible to one antiseptic than to another. 

 The most important are (1) bichloride of mercury, which is to be pre- 

 ferred on horses. It becomes weakened in its action if placed in a 

 wooden pail or on an oily or greasy surface. It is used in the strength 



