This may be suspected when in spite of much straining the urine is
habitually passed in a very fine stream, which has become finer and
finer for a length of time, without complete arrest as in calculus. The
introduction of a catheter will confirm the diagnosis and show the exact
seat of the stricture.
It is determined by irritation caused by calculus, urethritis, ulcer,
wounds, etc., which tend to the formation of a cicatrix encircling and
narrowing the canal. One efficient cause is the injection of strong
astringent or slight caustic solutions in the early stages of
urethritis.
_Treatment_ is by dilation, by bougies pointed and gradually thickening,
or simply by an elastic staff which at first passes with some force and
is replaced by a larger one as the urethra stretches under daily use.
=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found and slowly withdrawn from the sheath by steady traction.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.
=Catheterization in the Ram and Wether.= These must be dealt with like
the bull, the only additional difficulty being in the vermiform
appendix. This is small and sinuous but the longitudinal opening on its
lower surface is favorable to the introduction of the catheter.
=Catheterization in the Dog.= The fact that the urethra traverses the
groove on the lower aspect of the bone of the penis, is held to prove an
obstacle to the catheter, yet the introduction of the latter is in no
sense difficult. Small or moderately sized dogs, may be held upright,
the body resting on the rump and the pelvis inclined forward, which will
favor the spontaneous protrusion of the penis. Or it may be pressed out
by manipulation through the sheath. The catheter ⅔ ds. to 1 line in
diameter may be 1¼ to 2 feet in length according to the size of the
animal. It should be used aseptic.
=Catheterization of the Mare.= Nothing can be easier than this operation
in the mare. The shortness and dilatability of the urethra, and the
accessibility of its external orifice in the center of the floor of the
vulva, 4 or 5 inches in front of the lower commissure, favors the
introduction of the catheter. The latter may be a foot in length,
perfectly straight and it may be constructed of silver or some other
metal, which may be readily boiled and rendered aseptic. In the absence
of a catheter the germ free nozzle of a rectal syringe may be used, or
two fingers may be passed through the urethra and parted from each other
so as to allow the exit of the urine.
=Catheterization of the Cow and Heifer.= The operation is often very
difficult in the cow, by reason of the small size and undilatability of
the urethra, and by the presence of two blind ducts (canals of Goërtner)
above and to the two sides of the urethral opening. The thin rigid upper
margin of the orifice projects down over it in a valvular manner so that
the catheter will almost always find its way into one of the blind sacs.
By introducing the tip of the index finger beneath the valvular fold and
into the opening of the canal, the catheter may be directed beneath it
and into the bladder. An apparatus consisting of a series of ribs of
spring wire arranged in the form of a funnel and converging at one end
to a point has been devised to insert into the urethral orifice, and
guide the catheter which is passed through it.
=Catheterization of the Bitch.= The operation is rendered difficult by
the narrowness of the passage, and the puckers and folds of the vaginal
mucosa which serve to hide the urethral orifice. A small catheter like
that used on the male is used or a short metallic catheter may be
substituted. By directing this forward exactly in the median line of the
floor of the vulva, with gentle pressure downward it may be made to
enter the urethra. In case of special difficulty a bivalve speculum may
be resorted to, to efface the mucous folds and reveal the orifice.