This operation, which in the horse is confined to hæmorrhagic phlebitis, is especially applicable to phlebitis of the mammary vein in the cow. As the vein is subcutaneous, the operation may easily be performed in the standing position; the successive stages are as follows:—
The patient is firmly secured and its hind limbs hobbled by passing a rope around the hocks in a figure of eight. It is steadied on one side by an assistant who presses on the quarter.
One cubic centimètre of a 10 per cent. solution of cocaine is subcutaneously injected on each side of the vein at the point chosen. Ten minutes later a button-hole incision is made through the skin and a loop of thick catgut passed around the vein by means of a curved needle. The ligature is tied firmly with a surgical knot and the little wound afterwards covered with a mass of cotton wool secured by collodion.
INTERNAL INFECTIOUS PHLEBITIS (UTERO-OVARIAN PHLEBITIS).
The internal forms of phlebitis of parasitic or infectious origin are as yet little understood, but mention may be made of phlebitis of the utero-ovarian veins which frequently follows parturition and post-partum infection. This is probably in many instances the real cause of the post-partum paraplegia without gross or apparent material lesions.
This form of infectious phlebitis may extend to the large internal and external iliac veins and produce embolism and septicæmia, as is shown by recorded cases.
The mechanism of the disease is easily understood. The infective agents penetrate the veins of the uterine mucous membrane and pass from the lumen into the wall of the vein. Here they cause inflammation of the vascular endothelium, followed by the deposit of a fibrous clot of cylindrical form, which sets up partial thrombosis of the vein. This thrombosis becomes complete by the formation of a central clot due to venous stasis.
It is not necessary for the germs to penetrate at a number of points. The thrombosis progresses until it gains a large trunk beyond the original point of infection.
Symptoms. Phlebitis of the veins of the pelvis is frequently misunderstood or overlooked, because the practitioner is apt to confine his attention to external signs, the paresis and paraplegia of the hind quarters.
The symptoms usually appear from five to eight days after normal parturition or parturition in which there is retention of the after-birth followed by metritis. The animals show fever and lose appetite, signs which may be due to metritis, but soon after they experience difficulty in rising, and some days later remain permanently recumbent.