PERSISTEXCE OF THE rUArlll'S. 703 



CHAPTER III. 

 Persistence of the Urachus. 



In studying the development of the foetus the urachus was described 

 (pp. S2, 94), and it was pointed out that it is a canal formed by the 

 middle portion of the allantois, which passed throu^'h the umbilical 

 rin^', and durinj^ foetal life communicated with the bladder, from which 

 it conveyed the urine into the allantoid sac. After birth this canal is 

 obliterated, its walls become a thin cord, and the bladder is retracted 

 within the pelvic cavity, the urine tlien passing through the urethra. 

 It not unfrequently happens, however, that, from accidental circum- 

 stances or some malformation, the canal of the urachus is only partially, 

 or not at all obliterated after birth ; consequently, the urine continues 

 to escape by drops or in a thin stream from the umbilicus or umbilical 

 cord. This condition is far more frequent in Solipeds than in Ruminants, 

 owing to the urachus — like the umbilical artery — being firmly attached 

 to the umbilical ring in the former, and therefore not at once withdrawn 

 into the abdomen, as in the latter, when the umbilical cord is divided 

 at birth. Therefore it is Ihat escape of urine from the navel is very 

 seldom noticed in the Calf; while in the Foal it is often witnessed, 

 particularly when the abdominal ring remains very open, or the cord is 

 excised close to the body. This condition has, however, been seen in 

 Calves. 



It appears to be more frequent in male than female animals, and is 

 most serious in the former ; in the latter, the discharge of urine by this 

 abnormal channel often ceases spontaneously, only passing at first in 

 drops ; whereas, in the male it generally escapes in a stream, little or 

 no urine being discharged from the urethra. 



Treatment. 



In some cases scarcely any treatment is necessary, the escape of 

 urine ceasing in a few days after birth ; and when interference is 

 demanded, a cure can generally be effected in a short time if the urethra 

 is pervious. Benard' mentions an instance of this accident, in which 

 death occurred two days after applying a ligature to the urachus ; it 

 was then discovered that the urethra was imperforate, so that the urine 

 could not be expelled at all. It is therefore necessary, before adopting 

 remedial measures, to ascertain whether the urethra is patent. 



When the urachus protrudes sutViciently from the umbilical ring, a 

 ligature may be fastened firmly around it. When it is close to the 

 abdominal ring, and consequently too short to be tied by the ordinary 

 ligature, it must be secured by a curved needle. The Foal is thrown on 

 its left side, and the operator, holding the needle armed with the thread 

 in his right hand, seizes the urachus — which is covered by the skin — 

 between the thumb and index-finger of the left hand, and pulls it out- 

 wards ; the needle is then passed through behind the canal, including 

 as little of the skin as possible, and the ends tied. If there is any doubt 

 as to the patency of the urethra, the ligature should only be partially 

 tightened until the nature of the obsti-uction is ascertained and removed. 

 When this is done, then the ligature may be firmly tied, when the urine 

 escapes freely by the natural channel. 



^ Secue'tl lie Midtcine Viterinairt, 1828. 



