Catheterization. In connection with diseases of the bladder and urethra the passing of the catheter is a most important operation which requires considerable skill on the part of the operator. A short statement of the method to be adopted for each of the domestic animals will therefore be in place.
Catheterization in the male Soliped. The catheter, a hollow, gum elastic tube, must be proportioned to the size of the animal, but for the average adult horse about 3½ feet in length and ⅓ inch in thickness. To give it the requisite solidity and resistance it is usually furnished with a stilet of whalebone or cane.
The operation is performed with the animal standing, in quiet animals without any restraint, but in the more sensitive or restive, with one fore foot held up; or with both hind feet in hobbles furnished with ropes passing between the fore limbs and tied over the neck in front of the withers; or finally with a twitch on the nose.
The rectum is emptied, and with the oiled or soapy hand the penis is found and slowly withdrawn from the sheath by steady traction. This is usually easy, though in certain cases, with a short penis and specially strong retractors, it will seriously tax the operator’s skill and address. In a specially obstinate case a hypodermic injection of morphine may be resorted to.
If the horse is down, as in paraplegia or hæmoglobinæmia, he may lie on his right side while the operator stoops over him from the loins; or his feet may be drawn together by hobbles, and the subject turned on his back, the operator placing himself as before on the left side.
The catheter must have been previously cleansed and disinfected outside and in. A mercuric chloride solution 1:2000, or boric acid 1:50 or permanganate of potash 1:50 may be employed. Then it must be smeared, preferably with vaseline but, in case of necessity, with sweet oil, glycerine, borated lard, or even castile soap.
The penis being withdrawn from the sheath, the catheter containing its stilet is introduced into the urethra and pushed on slowly and carefully until its point can be felt over the ischiatic arch. The stilet is now drawn out a few inches and the point of the catheter is bent forward over the ischium by the finger. The stilet is further drawn out and the catheter can easily be pressed on into the bladder. If any difficulty is experienced it may be guided by the hand introduced into the rectum.
In one extraordinary case, I found that the catheter entered a dilated seminal vesicle and failed to evacuate the bladder. This untoward occurrence must be rectified by the aid of the hand in the rectum. Usually the penetration of the bladder is signalized by the overcoming of resistance, and when the stilet is withdrawn the urine flows in a steady stream. If it fails to flow, a slight compression of the fundus of the bladder by the hand engaged in the rectum will start the stream.
The catheter should be withdrawn slowly and carefully.
Catheterization in the Bovine Male. Most veterinarians suppose that this is impossible, owing to the narrowness of the sheath interfering with the extraction of the penis, and the S shaped curve in the penis preventing the introduction of the catheter. Both obstacles can, however, be overcome in many cases. The bull may be tempted to protrude the penis by the presentation of a cow in heat, or in bull or ox the bulging anterior part of the organ may be protruded by careful manipulation through the sheath. Then the free extension of the penis can be made to efface the S shaped curve. The catheter must be small, not much over a line in caliber, and a metal stilet is employed. The animal may have to be placed under restraint, and the same antiseptic precautions are demanded as in the horse.