244 DISEASES OF CATTLE. 



Avith the knife and sewed up again or closed Avith collodion, but such 

 an operation is best deferred until the cow is dry. 



TEAT BLOCKED BY A WARTY OR OTHER GROWTH INSIDE. 



In this case the obstruction may be near the orifice of the teat or 

 farther up, and the solid mass is not movable up and down with the 

 same freedom as are concretions and calculi. The movement is lim- 

 ited by the elasticity of the inner membrane of the teat from Avhich it 

 grows, and is somewhat freer in certain cases because the growth has 

 become loose and hangs by a narrow neck. In the case of the looser 

 growths they may be snared by a fine, spring Avire passed as a loop 

 through a fine tube (like a teat tube open at each end) and introduced 

 into the teat. When this can not be done, the only resort is to cut 

 in and excise it Avhile the coav is dry. 



THICKENING OF THE MUCOUS MEMBRANE AND CLOSURE OF THE 

 MILK DUCT. 



As a result of inflammation extending from Avithout iuAvard, a 

 gradual narrowing of the milk duct may occur from thickening and 

 narroAving of its lining membrane. This may be limited to a small 

 area near the lower end, or it may extend through the Avhole length 

 of the teat. The stream of milk becomes finer and finer until it 

 finally ceases altogether, and a firm cord is felt running through the 

 teat. If the constriction is only at the outlet, the teat may be seized 

 and distended by pressing the milk down into it from aboA'e, and an 

 incision may be made Avith a sharp penknife in two directions at right 

 angles to each other and directly in the original opening. The knife 

 should be first cleansed in boiling Avater. The opening may be kept 

 from closing by a dumb-bell shaped bougie of gutta-percha (PI. 

 XXIV, fig. 5) or by the spring dilator. If the obstruction is more 

 extended it may be perforated by Liithi's perforating sound. (PI. 

 XXIV, fig. 1a and 1b.) This is a steel Avire Avith a ring at one end, 

 and at the other is screAved on to the wire a conical cap Avith sharp 

 cutting edges at the base, A\'hich scrapes aAvay the thickened masses 

 of cells as it is draAvn back. This may be passed again and again to 

 enlarge the passages sufficiently, and then the passage may be kept 

 open by Avearing a long, dumb-bell bougie, a thick piece of carbolized 

 catgut, or a spring dilator. If the passage can not be sufficiently 

 opened Avith the sound it may be incised by the hidden bistoury. (PI. 

 XXIV, fig. 2.) This is a knife lying alongside a flattened protector 

 Avith smooth, rounded edges, but which can be projected to any re- 

 quired distance by a lever on the handle. The incisions are made in 

 four directions, as deep as may be necessjiry, and the Avails then 

 can be held apart by the spring dilator until they heal. In case the 



