82o Diseases of the Genital Organs 



clots or become purulent. The necrosis may extend to the 

 bones, as illustrated in Fig. 235. 



E. Re-Opening of the Urachus 



The closing of. the urachal stump, when it retracts into 

 the abdomen immediately after the rupture of the navel 

 cord, is ordinarily secure. It is brought about partly by 

 the thickening of the walls of the tube in the process of 

 shortening, partly by the retraction of the surrounding con- 

 nective tissue sheath, and apparently also by lymph poured 

 out from the lacerated walls at the point of rupture. If the 

 urethra is open and the umbilicus escapes infection, no 

 urine escapes from the umbilicus. If infection invades the 

 wounded umbilic tissues and the urachal stump is involved, 

 the urachal canal re-opens and urine flows from the navel. 

 Apparently it does not matter whether the invasion is ex- 

 trinsic or intrinsic, the re-opening of the urachus follows. 

 The umbilicus then becomes saturated and infiltrated with 

 urine and much decomposition results. It has been assumed 

 generally that in these cases the urachus has failed to close, 

 but according to my observations the open urachus (assum- 

 ing the urethra is open) is uniformly secondary to infec- 

 tion and never primary. 



The handling of this group of infections has not been well 

 standardized. Fundamentally the principles involved are 

 identical with those applying to calves. The rule laid down, 

 that the sole guarantee for the birth of a sound calf is de- 

 pendent upon the mating of sound parents, is equally appli- 

 cable to horsebreeding. 



It is essential to the safety of a new-born foal that the 

 expulsion of the meconium should be caused as completely 

 and early as practicable. The safest means is the high 

 enema, as recommended for calves. The enemas should be 

 repeated at least twice daily until the expulsion is complete 

 and soft meconium is passed. When meconic retention be- 

 comes evident, it should be attacked vigorously. The enemas 

 of physiologic salt solution should be frequent and as high 

 as practicable. Olive or cottonseed oil. or liquid paraffin 



