[26] Leg evil ought properly to be classed with diseases of the vascular system, being in many instances merely a symptom of disease in the heart or great vessels; but as the same results are arrived at by placing it under the present head, nicer distinctions would only tend to create confusion. (122.) _Blown or Blast._ Can scarcely be reckoned a disease as it is but a symptom caused by a mechanical impediment to respiration and circulation. When a sheep has been brought from a poor pasture to a rich one it is prone to gorge itself to an extent which may endanger life. The lower end of the gullet becomes obstructed, the gases which accumulate in the paunch are hindered from escaping, and the latter becomes so enormously distended as speedily to suffocate the animal by being forced into the chest. (123.) _Treatment[27] of Blown._ If the difficulty in breathing be only slight, keep the sheep moving _gently_ up and down as the air will thus have a chance of escaping from the stomach. If the symptoms are more alarming, pass the elastic tube employed in the same complaint in cattle down the throat, or if that cannot be procured use a cane with an ivory or wooden bullet at the end of it. Never _stick_ the animal, as recovery by this plan is almost hopeless. If you cannot obtain the aforesaid instruments, bleed the animal till it becomes very faint, and if this is of no avail proceed to kill it. Shepherds often prescribe a purgative dose after this occurrence. In general, however, it is not required. To prevent a flock becoming _blown_, always when, for the first time on rich pasture, make the dog move leisurely among them so as to prevent them feeding hastily. [27] In speaking of remedial measures, the word treatment ought to be used in preference to "_cure_" which figures at the head of the medical advice in veterinary works. It is sheer nonsense to blazon such a word in pages having any pretentions to candour, for how seldom are we able conscientiously to affirm that our endeavours will be followed by a _cure_. All we can do is to pursue the _treatment_ best adapted for the attainment of so desirable an end.