DISEASES OF DOMESTIC ANIMALS. 11 



or a bruise on the shoulder. When you examine it, you find it contains 

 fluid — blood and water — not pus ; this is an example of effusion. It 

 comes from a slight injury to the areolar tissue, no doubt. 



Suppuration or the Formation of Pus. — Pus presents two parts for 

 consideration, a liquid and a solid ; and corpuscles being the solid. It 

 may take place in different ways, or in different forms — circumscribed, 

 diffused and superficial. 



Circumscribed, as an abcess, or from injuries to the shoulders or 

 muscles. Pns is formed from blood cells, and is known as a yellowish 

 wbite fluid, ordinarily inodorous, but in fistula, etc., it becomes fetid. 



Dijfuse Suppuration, as in glanders and injuries to the large muscles, 

 as in the gluteal region. 



Superficial, as in the mucous membranes. Some mucous membranes 

 do not form much pus, while others do ; examples of the latter are 

 those of the nose and generative organs. There are inflammatory 

 tumours, as in strangles ; they are at first hard, then soft, then burst. 

 This is a circumscribed suppuration. It breaks down the tissues and 

 finds its way to the outside, or pus may remain for some time in the 

 tissue, as in abcesses in cattle. It may remain much the same for a 

 considerable length of time, but if punctured dtep pus may be found. 

 Suppuration is sometimes favorable, as in a case of injury from a nail 

 in the foot, matter forms and escapes and relief is afforded. When 

 blood or its colouring mater is mixed with pus, it is called sanious pus. 

 If pus is continued for some time in connection with a diseased bone or 

 tooth, it becomes very fetid in many cases. Pus is sometimes found 

 with active properties. It flows from a wound over the skin, it destroys 

 the hair or skin, and is called ichorous pus. If pus is mixed with 

 poison, as that of glanders, etc., it is called specific pus, for it will pro- 

 duce the same disease. Laudable pus has no smell. Diffuse suppuration 

 may occur in some internal organ, as the lungs, and is called purulent 

 infiltration. In injuries to the groin or withers, if there is danger of 

 erysipelatous inflammation, or danger of it running on to gangrene, 

 diffuse suppuration is sometimes desirable. It is superficial when in the 

 skin or mucous membranes. 



Ulceration. — This may be called molecular death of a part, and 

 generally arises when the tissues degenerate and are thrown off in large 

 amounts. There are different kinds of ulcers. Some will heal readily 

 while others will not. The ulcers of glanders will not heal. Ulceration 

 is frequently produced by continued inflammatory action. When the 

 vitality of a part is greatly depressed, or the general powers of the con- 

 stitution are weakened, ulceration is likely to take place, the state of the 

 system tending to help it. 



Gangrene, or Mortification, is death of a part, either in its entirety or 

 a portion of greater or less size, and may proceed from direct injury to a 

 part, and is the result of intense inflammation. When it involves any 

 important organ, or is extensive, it creates great constitutional dis- 

 turbance, acting upon the heart. The pulse becomes weak and indistinct, 

 ending in death, and a large portion of the bowels may be found in a 

 gangrened condition. But if it affects but a small part, there is not 

 much constitutional disturbance. Even a small part of the lungs may 

 become so and the animal live for some time. If a part dies from gan- 

 giene, it acts as a foreign body to the tissues surrounding it, and, like 

 all foreign bodies, sets up an irriiation in the surrounding tissues, which 

 continues, and the surrounding tissues are converted into pus, and the 

 dead part is so removed from the body. We frequently assist nature in 

 this by assisting the sloughing piocess. There are acute, sub-acute and 



