188 PRINCIPLES OF VETERINARY SURGERY 



motic when the spots are larger and fuse together, and 

 thus discolor a considerable surface. When a very large 

 surface is involved the w^ord extravasation is usually ap- 

 plied. And finally it is called infarction when tissues be- 

 come saturated with more or less blood fr.om obstruction of 

 capillaries or veins. Haematoma is used to designate the 

 collection of a considerable amount of blood in the tissueSi 



Haemophilia is that condition in which there is a tend- 

 ency to bleed profusely on slight provocation. The disease 

 exists without any perceptible abnormality of the organism. 

 The patient bleeds for hours and often for several days from 

 a trivial abrasion and every effort to arrest the flow may 

 fail. It is said to be hereditary. In the human being the 

 female bleeder transmits the condition to her male off- 

 spring. In animals hsemophilia is occasionally encountered 

 in asses, and mules, and in certain individual horses. The 

 most rational explanation of the phenomenon, and the one 

 most generally accepted, is that the condition depends upon 

 an aberration of blood coagulation. There is no perceptible 

 alteration in the blood vessels, or in the general welfare or 

 health of the patient. The true nature of the condition is, 

 however, little understood. 



Certain special names are applied to haemorrhages from 

 different organs, as follows : — Haematuria is bleeding from 

 the urinary channel, haemoptosis, from the lungs, epistaxis 

 from the nasal cavities, enterorrhagia, from the boweis, 

 haematomesis, from the stomach, and menorrhagia, from the 

 uterus. 



Haemorrhage is also classified into primary when it oc- 

 curs immediately after infliction of the injury; and second- 

 ary when it occurs some time after the injury from slough- 

 ing of tissues or ligatures. 



ARTERIAL HiEMORRHAGE.— Haemorrhage from 

 arteries is more serious than that from veins of the same 



