TREATMENT. 275 



solution, which in some cases is taken in the drinking-water ; 

 but if not, it must be exhibited in draught. 



A very good preparation in many of these conditions is 

 Donovan's solution, given in moderate but repeated doses for 

 some time. 



Externally, the most useful form is the compound iodine 

 ointment, applied with gentle friction all round, but chiefly on 

 the inner surface of the limb, once daily. This last treatment 

 may be persevered with even while the horse is doing moderate 

 Avork, which, if it is possible for it to engage in, is rather an 

 advantage than otherwise. Issues, in the forms known as 

 rowels or setons, smart blistering, or even the actual cautery, 

 applied over different parts of the limb, have been, and are 

 even yet, employed, with a view to reduce the unsightly swell- 

 ing, and thereby restore the natural freedom of movement ; 

 none of these, however, seem to yield results superior or even 

 equal to the more easily applied and more humane treatment 

 which has already been indicated. 



CHAPTER XVI. 



PURPURA HyEMORRHAGICA. 



Definition. — A general or systemic disease intimately con- 

 nected ivith or having its origin i)i extensive changes of the 

 blood and capillary bloodvessels, cha.racterized by the presence 

 of yetechicG or blood-spots on the mucous membranes, and by 

 the existence of elevations of the cutaneous tissue. From 

 the mucous membranes there is hcemorrhage, and from the 

 cutaneous siuellings an oozing of bloody coloured serum. 

 There is also a disposition to blood-extroA'asations in internal 

 organs. 



Pathology, a. Nature. — Although the diseased condition of 

 the horse recognised by the term Purpura hemorrhagica is now 

 pretty well loiown, and is rarely confounded with any other, 

 there is yet Uttle agreement as respects its pathology, which, 

 besides being disputed, is but imperfectly understood. We 

 are not agreed as to the interpretation of, or the value which 

 ought to be placed on, the several symptoms which mark the 



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