STENOSIS AND CLOSURE OF THE TEAT DUCT. 717 



The diagnosis of this condition offers no difficulty, though the 

 discovery of the cause is sometimes a hard task. Congenital closure 

 will be recognised on the first calving by the excessive distension 

 of the udder and teat, and by the fact that no milk flows when the 

 parts are compressed. The little piece of skin covering the opening 

 of the teat visibly protrudes, and on attempting to pass a probe, 

 no opening can be found in the teat ; the same is the case in adhesions, 

 in which, however, indications of an opening exist. 



In stenosis or occlusion of the duct the probe either passes with 

 great difficulty or not at all. The milk escapes in a thin stream, 

 while the animals evince pain by kicking or moving about. Stenosis, 

 caused by proliferation of the epithelium or thickening of the mucous 

 membrane, can be felt as a cord-like swelling when the teat is rolled 

 between the finger and thumb. Induration in the upper portions 

 of the teat may similarly be detected, whilst, in closure by folds of 

 mucous membrane, palpation gives a negative result, and the probe 

 meets with a somewhat yielding obstruction in the depth. This 

 valve-like closure is occasionally indicated by those portions of the 

 galactophorous sinus above the valve gradually becoming filled 

 with milk and increasing in diameter, whilst those below appear 

 small, and are generally occupied by a clear watery fluid, which, 

 according to Larsen, always contains bacteria (cocci or bacilli). A 

 small quantity of this fluid may from time to time be discharged. 

 Sometimes the valve can be thrust on one side with the probe, and, 

 for the time being, the milk allowed to flow freely away. 



Treatment. The stenosed teat duct may be dilated by repeatedly 

 introducing bougies ; thick catgut threads, 1 to H inches long, 

 provided with a knot at one end, so that they cannot slip completely 

 into the duct, may be passed a couple of hours before or immediately 

 after milking, and allowed to remain in position for some hours. 

 They can be used more than once, but, to prevent infection and 

 mastitis, the bougies should be carefully cleansed and dried on each 

 occasion. The same is true of all other instruments, such as milk 

 catheters, probes, &c, which must be carefully cleansed and 

 rendered absolutely sterile. Particular care is required where the 

 teat is inflamed, as in cowpox, aphtha, &c. 



If for any reason the mammary duct cannot be dilated in this 

 way it may be incised, or the end of the teat amputated. For the 

 former purpose a narrow, straight tenotome, or specially-constructed 

 " milk needle," consisting of a slender double-edged fistula knife, 

 is employed. The operation is easiest with the udder distended. 

 The animal is held with " bulldogs," the teat grasped with the left 



