20 HORSE, SWINE AND POULTRY DISEASES 



small blood vessels in the skin have contracted and are keeping the 

 blood away, as during a chill, or that the heart is weak and is unable 

 to pump the blood to the surface, and that the animal is on the verge 

 of collapse. 



The skin is moist, to a certain degree, at all times in a healthy 

 horse. This moisture is not in the form of a perceptible sweat, but it 

 is enough to keep the skin pliable and to cause the hair to have a soft, 

 healthy feel. In some chronic diseased conditions and in fever, the 

 skin becomes dry. 



When, during a fever, sweating occurs, it is usually an indica- 

 tion that the crisis is passed. Sometimes sweating is an indication of 

 pain. A horse with tetanus or azoturia sweats profusely. Horses 

 sweat freely when there is a serious impediment to respiration ; they 

 sweat under excitement, and, of course, from the well-known physio- 

 logical causes of heat and work. Local sweating, or sweating of a 

 restricted area of the body, denotes some kind of nerve interference. 



Swellings of the skin usually come from wounds or other exter- 

 nal causes and have no special connection with the diagnosis of inter- 

 nal diseases. There are, however, a number of conditions in which 

 the swelling of the skin is a symptom of a derangement of some other 

 part of the oody. For example, there is the well-known stocking, or 

 swelling of the legs about the fetlock joints, in influenza. There is 

 the soft swelling of the hind legs that occurs so often in draft horses 

 when standing still and that comes from previous inflammation or 

 from insufficient heart power. Dropsy may occur beneath the chest 

 or abdomen from heart insufficiency. 



Wounds of the -skin may be of importance in the diagnosis of 

 internal disease. Wounds over the bony prominence, as the point of 

 the hip, the point of the shoulder, and the greatest convexity of the 

 ribs, occurs when a horse is unable to stand for a long time, and, 

 through continually lying upon his side, has shut off the circulation 

 to the portion of the skin that covers parts of the body that carry the 

 greatest weight, and in this way has caused them to mortify. Little, 

 round, soft, doughlike swellings occur on the skin and may be scat- 

 tered freely over the surface of the body when the horse is afflicted 

 with urticaria. Similar eruptions, but distributed less generally, 

 about the size of a silver dollar, may occur as a symptom of dourine, 

 or colt distemper. Hard lumps, from which radiate welt-like swell- 

 ings of the lymphatics, occur in glanders, and blisterlike eruptions 

 occur around the mouth and pasterns in horsepox. 



The Organs of Circulation. The first item in this portion of the 

 examination consists in taking the pulse. The pulse may be counted 

 and its character may be determined at any point where a large ar- 

 tery occupies a situation close to the skin and above a hard tissue, 

 such as a bone, cartilage, or tendon. The most convenient place for 

 taking the pulse of the horse is at the jaw. The external maxillary 

 artery runs from between the jaws, around the lower border of the 

 jawbone and up on the outside of the jawbone to the face. It is lo- 

 cated immediately in front of the heavy muscles of the cheek. Its 

 throb can be felt most distinctly just before it turns around the lower 



