ATRESIA OF THE LACTEAL DUCT 127 



ATRESIA OP THE LACTEAL DUCT 



Atresia of the lacteal duct is commonly termed teat 

 stricture. The occlusion is usually a partial one, 

 rarely complete. The seat of stricture or closure may 

 be at the teat orifice, along the course of the duct, or 

 at the proximal end of the duct where it emerges from 

 the sinus lactiferus. 



When the stricture is located at the apex, or near 

 the distal end, the milk enters the teat quite readily 

 but difficulty is experienced in squeezing it out; the 

 stream is very thin, or it squirts in several directions. 



When the stricture is farther up, or at the proximal 

 end, difficulty is experienced in getting the milk to fill 

 up the teat; after the teat is filled it is ejected easily. 



In rare cases, which may oecur in heifers, there is 

 a triie atresia or closure of the duct orifice in the end 

 of the teat. There is only a slight pit or depression 

 in the epithelium, at the point where the duct nor- 

 mally emerges, but the epithelium is not perforated. 



With two exceptions, strictures of the teat have an 

 unfavorable prognosis. One exception is that form 

 occurring at the very extremity or external orifice of 

 the duct; the other exception is that form appearing 

 as a true atresia in heifers. 



In the various forms involving the duct higher up 

 and at its proximal end the treatment is not very 

 well understood nor accompanied by satisfactory re- 

 sults. Of course, there are cases of the latter variety 

 occasionally which have a satisfactory termination, 

 but they are rare. The treatment which is in vogue 

 for these conditions (and to all appearances as good 

 as we can do) is fraught with danger from the stand- 



