496 FISTULOUS WITHERS. 



used, with such precautions as a smooth piece of waxed linen sewed 

 into the flaps, where they overlie the damaged spot. Where a felt 

 numnah is used, a piece corresponding in size and position to the 

 injury may be cut out ; where a padded saddle is in use, a portion 

 of the padding can be withdrawn. This protects the tender surface 

 while it is denuded of hair and only covered with a thin epidermis. 



Injuries to the withers, particularly those complicated with 

 exudation and extravasation into the subcutis, require quite different 

 treatment. In fresh cases cold is useful, but without pressure and 

 without massage. Any considerable pressure usually causes pain, 

 while massage favours further bleeding into the subcutis. After 

 twenty-four hours, moist warmth is to be preferred. To prevent 

 infection and pus formation, an antiseptic can be added to the 

 compresses, which may be prepared with 1 per 1,000 sublimate 

 solution. Where the tenderness is less, and large haematomata 

 exist, massage may later be used. Artificial removal of the contents 

 may here be recommended, using a Pravaz's syringe, though antiseptic 

 precautions must in such case be very carefully observed. Both 

 the skin and instrument must first be disinfected ; and, after removal 

 of the extravasation, moderate pressure should be maintained by 

 means of antiseptic dressings to prevent recurrence. Particular 

 care is required in using the knife, and fluctuating swellings must 

 only be opened when it is quite clear that pus exists. It is preferable, 

 in doubtful cases, to employ a blister of cantharides, or biniodide 

 of mercury, by which a swelling is caused and moderate pressure 

 produced on the extravasated material, bringing about resorption. 



Pus formation in the region of the withers renders treatment 

 very difficult. Removal of pus and necrotic material, and prevention 

 of fresh infection and necrosis are the chief objects to be sought in 

 these cases. The knife must often be used freely. Sinuses should, 

 if possible, be laid open to their extremity, pockets exposed, and 

 necrotic pieces of lig. nuchge, of fascia and of superior spinous pro- 

 cesses removed as soon as possible. Gauze or rubber drains assist 

 the escape of the discharge, and prevent further extension of infection. 

 In the event of pus forming beneath the muscles, these are laid open, 

 but care must be taken not to divide the skin crosswise over the 

 middle line of the back, because in this way wounds result, which 

 heal with difficulty on account of tension or of their edges turning 

 inwards. Sometimes suppuration extends to the muscular tissue 

 of the neck, which must then be laid open, usually as deeply as the 

 lig. nuchse, which, as in poll-evil, may require to be partly excised. 

 In such exceptional cases Hertwig and many others recommend 



