MANAGEMENT OF THE FOAL 
69 
the uterus almost immediately after the expulsion of the fetus and comes 
away with cord still intact. It is then ruptured later by the struggles 
of the fetus itself. The mare may step upon some portion of the mem¬ 
branes when the foal is attempting to get up, and the foal, in falling, 
throws its weight upon the cord in such a way as to rupture it. 
• • In examining the navel cord of the foal, one finds that im¬ 
mediately against the umbilicus there is a dense area extending for a 
distance of about 1 V 2 inches which changes somewhat abruptly at a 
marked ring to the soft umbilic cord. This projection consists of a hair¬ 
less skin, wliich, in the healing of the navel, atrophies and disappears. 
Just beyond this point, one or two inches from it in the foal, is the 
weakest point in the cord, where it ruptures or is torn in two. 
“The rupture of the umbilic cord stands a part as a universal physiolog¬ 
ic wound, which under favorable conditions pursue a course in healing 
which fulfills the highest ideals of surgery. The processes involved in 
the healing of the wound include prompt and efficient hemostasis, 
thorough drainage, and the rapid aseptic desiccation of a large mass of 
necrotic tissue, which hermetically seals the tissue of the young animal 
against invasion by bacteria. In normal environment, these fundamental 
processes of repair proceed perfectly and rapidly, far more safely than 
the healing of accidental or surgical wound, in the hands of many sur¬ 
geons. The hemostasis is notable for its promptness and perfection in 
detail. The umbilic arteries, usually ruptured by linear tension, at a 
distance of about two inches outside the umbilicus . . . recoil elastic 
cords, and their broken ends come to rest at or near the urachal end, or 
fundus, of the urinary bladder . . . The ruptured ends are somewhat 
fibrilated, their walls become greatly thickened as a consequence of the 
recoil, and their lumen becomes virtually eliminated. The recoiling 
artery drags the loose perivascular connective tissue with it, invaginat- 
ing the fibrous mass to form an intricate entanglement which serves as 
an impassable barrier to blood. A few drops of blood, and only a few, 
escape from the broken ends of the arteries, to constitute a very limited 
extravasate. The broken arteries then rest far afield from any threaten¬ 
ing infection . . . The fetal end of the urachus, flanked on the right 
and the left by the umbilic arteries, retracts with them into the perito¬ 
neal cavity and comes to rest two or three inches above and behind the 
umbilicus. The behaviour of the urachus is parallel to that of the arteries; 
no urine escape from it physiologically. Pathologically, if the urethra is 
not open, the pressure of urine within the bladder forces open the re 
cently ruptured tube, and the urine escapes through the navel. This 
is exceedingly rare . . . Not infrequently when the cord is ligated 
and the urachus held in the decaying umbilic stump—less commonly 
when the umbilic stump is let alone—the urachus reopens, similarly to 
the secondary hemorrhage of infection. 
“The umbilic vein, without material retractile power, remains in its 
original position after its rupture. Immediately after its rupture, most 
of the blood contained in it at the moment falls away exteriorly. Per¬ 
haps some of its blood—how much is unknown—is drawn into the auricle 
and remains a part of the living blood mass. The absence of valves in 
the vein permits an almost perfect drainage. As soon as the chief volume 
of blood has escaped, the thin-walled vein collapses, retaining only a 
very small amount of blood. If, however, the vein is ligated prior to the 
escape of the blood, it becomes imprisoned, necrotic, and subject to the 
same laws of decay as a hematom in a wound. After the vessel has 
collapsed, its walls adhere, and it remains in the adult as a fibrous vestige 
constituting a small ligament passing from the umbilicus to the liver. 
This behavior of the umbilic stump is highly important in relation to 
the well-being of the young, since through this portal serious infection 
frequently occurs to constitute the disease known as navel infection, or 
omphalo-phlebitis. 
