NAVEL ILL. 533 



which constitute the after-birth on delivery. These membranes are 

 attached to the wall of the womb, and are connected to the foetus by 

 means of the navel-string (umbilical-cord), which is provided with 

 two arteries and a vein for the nourishment of the young creature 

 and for the removal of its waste products. It also has a narrow 

 canal (the urachus) which serves to remove the urine of the foetus ; 

 in fact, the subsequently formed bladder takes its origin from a 

 dilation of the urachus. Under normal conditions, when the 

 foal is born, respiration takes place, the umbilical arteries and 

 vein become quickly blocked up, urine is discharged through the 

 urethra (which communicates with the penis or vagina, as the 

 case may be), the foal enjoys a separate existence, and the wound, 

 caused by the division of the umbilical cord, leaves a scar which 

 is known as the navel. 



It is usually supposed that the microbes of navel ill gain admit- 

 tance into the body through the exposed surface, before the wound 

 has closed. We read, however, in the " Veterinary Record" of 14th 

 Dec, 1901, that Schule, who is Head Veterinary Surgeon at the 

 Wurtemburg State Stud in Marbach, has shown that " the mother 

 is the bearer of the infection, for in the uterine secretions of the 

 stud mares whose foals fell with navel-ill, the same characteristic 

 bacteria were found as were present in the joints of the affected 

 foals. The infectious material is by the act of covering conveyed 

 from mare to mare, so that the mucous membrane of the womb 

 becomes the habitat of the specific bacteria. 



" By inoculation of these bacteria into the blood stream of foals 

 an illness was produced, which in the smallest particular could not 

 be distinguished from that arising in naturally affected foals." 

 If the infected microbes are transmitted by the dam, it is a strange 

 fact that their presence does not jDroduce any disturbance in her. 



INFLUENCE OF LOCALITY.— Although, as a rule, this is a rare 

 disease, it is very common in some places. Mr. Wharam, M.R.C.V.S., 

 tells us ("Veterinary Record," 11th May, 1901) that " I have known 

 several instances on particular farms, where they were unable to raise 

 either foals or calves, but if removed to another farm, immediately 

 after or before foaling, the foal lived, and was reared without diffi- 

 culty, and although constitutional debility jDlays an important part, 

 the presence of specific organisms constituting an infected area is, I 

 believe, the most important factor in producing this disease." 



MORTALITY. — According to Hering and Bollinger, about 75 per 

 cent, of the cases die within the first three weeks after birth. This 

 high rate of mortality would be considerably diminished, if proper 

 treatruent was adopted. 



