7 18 PA THOLOG Y OF PARTURITION. 



necessary. Various instruments have been proposed for this operation, 

 but Ltithi's sound is perhaps the best. This is an iron wire about eight 

 millimetres long and two in diameter, having a ring at one end, and at 

 the other a steel cone screwed on to it. This cone has a very sharp 

 point, and both sides have cutting edges at the base or widest part. It is 

 passed into the opening of the teat, pushed through the obstacle, and then 

 gently turned round from side to side until no resistance is felt. Then 

 it is withdrawn, and a bougie or teat-syphon, or a piece of thick earbol- 

 ized catgut introduced. Zundel mentions that Ltithi and Strebel have 

 been very successful by this method of operating. 



B 



Fig. 209, 



LuTHi's Perforating Sound. 

 A. Half the Natural Size. B. Natural Size and Section of the Cone. 



In all cutting operations on the teat, every precaution must be adopt- 

 ed for the prevention of mastitis ; and this must chiefly consist in follow- 

 ing out the antiseptic method of treatment of the incisions as closely as 

 possible. 



Fistula of the Teat. 



We have seen several cases of fistula of the teat which proved very 

 troublesome to cure during the period of lactation. From injury or 

 disease, an opening is established between the milk sinus and the side of 

 the teat ; so that the milk, instead of passing through the canal in the 

 extremity, escapes in a jet at the side, and its flow is nearly constant. 

 This is a source of loss, and has often an unpleasant appearance. If it 

 is decided to cure the fistula during the lactation period, and the opening 

 is towards the middle of the teat, then the ring teat-syphon must be kept 

 in the sinus for some time, and the fistula treated according to surgical 

 principles. When the fistula is towards the extremity of the teat, how- 

 ever, the case is more difficult, and the teat-syphon only too often renders 

 it worse. Then it is generally necessary to wait until the Cow is " dry," 

 when, with a little attention, the fistula is readily cured. 



