It is more especially in stallions advanced in years, and who have been much used at the stud, that inguinal hernia calls for active treatment. Here.the internal abdominal ring having become enlarged, a knuckle of intestine is permitted to enter the inguinal canal. If in this confined space it becomes distended with food and gas, as is most likely to occur, the pressure from within and the resistance from without, by interfering with the circulation, ends in swelling and strangulation of the gut at or about the internal abdominal ring. It is under these circumstances that symptoms are developed which draw attention to the disease. The animal is restless, paws the ground, stretches himself out, and gives evidence of abdominal pain by looking back at the flank, crouching and lying down, or he sits on his haunches like a dog. The hind-limbs are moved somewhat stiffly in progression, and the testicle on the affected side in particular rises and falls. Unless relief is afforded inflammation attacks the extruded parts, the pain becomes more severe and persistent, the scrotum and flank are bedewed with perspiration, the pulse is increased in frequency, and the breathing becomes quick and panting.
The occurrence of some or all of these symptoms in a stallion should always excite suspicion, and no time should be lost in the application of appropriate means of diagnosis. If inguinal hernia exists, the spermatic cord by which the testicle is suspended will be found to be more or less swollen, but the most reliable indication of the disease is afforded by passing the greased hand well into the rectum. If, when this has been done, the hand is directed downward and outward, it will be brought into contact with the internal abdominal ring, where, if present, the imprisoned gut will be felt.
From the previous remarks it will be gathered that the treatment in inguinal hernia is not necessarily required save when the hernia is strangulated, or the operation of castration is to be performed. Before resorting to extreme measures, it is always desirable to attempt to extricate the bowel from its abnormal position by ordinary manipulation, in which case the rectum is first emptied of its faecal contents, and then the hand, having been well anointed with vaseline or oil, is introduced into it and carried as directed above to the internal abdominal ring. By a little careful traction on the imprisoned gut it may sometimes be liberated without further trouble. If it cannot be done so, the horse must be cast and put Tinder the restraining influence of chloroform. In this condition he is placed on his back, the hind-quarters are raised by underpacking with straw, and the hind-leg on the side of the hernia is drawn slightly forward and away from the body. In this position the food contents of the displaced gut are encouraged to return into the more depending part of the bowel, and by reducing the volume of the hernia its withdrawal from the inguinal canal is facilitated. One hand should now be introduced into the rectum and gentle traction again made on the imprisoned bowel. At the same time an assistant will appose the palm of his hand or hands to the hernia, and while applying gentle downward pressure to the base, will carefully manipulate the neck with the fingers in such a way as to cause the food and gas confined within it to pass out, and by still further reducing the size of the imprisoned mass hasten its return.
Promise of success will be indicated if the enlargement diminishes in size and the bowel shows a disposition to yield to the traction from within. If, however, no change is perceptible in these respects after reasonable effort, the attempt should cease until the imprisoned gut has been released by surgical operation.
PLATE XXVII. HANOVERIAN.
The Property of His Majesty King Edward VII
Where strangulation is known to have existed for some time this should be resorted to at once without delay.
Under such circumstances the intestine will he inflamed, swollen, and soft, and may be easily torn or fatally damaged in any attempt to relieve it by taxis.
The operation referred to (herniotomy) consists in enlarging the internal abdominal ring in order to remove the constriction and allow the gut to pass back into the belly.
For this purpose the patient must be kept under the influence of chloroform and strict antiseptic methods observed. The skin and underlying membrane (dartos) are cut through and carefully dissected from the peritoneal sac (tunica reflexa) in which the gut is contained. A small opening is now made into the sac, and the finger passed along it in the direction of the internal ring; in search of the constricted spot. When this has been found the herniotome is passed into the opening, and, following the finger, is brought to the seat of strangulation; the back of the instrument is then turned towards the bowel, and the blade towards the outer part of the ring. It is now brought into action by opening the handles. A very slight incision is sufficient to set free the strangulated bowel, unless, as a result of inflammation, it has become adherent to the sac.
Should this be found to be the case the adhesions must be carefully broken down with the finger and the parts returned.
Castration by the "covered operation" should follow liberation of the gut. In this method the tunica vaginalis reflexa and the spermatic cord are securely included between a pair of clamps, which must be adjusted as high up above the testicles as possible. After the wound has been freely dressed with some antiseptic dressing the patient is allowed to rise.
Williams, in his Principles and Practice of Veterinary Surgery, in referring to this operation, observes: "I consider this method a very undesirable one, and calculated to be succeeded by very unsatisfactory results; and even if it were always successful, I fail to see the advantage of dissecting the skin and dartos muscle from the tunica vaginalis, and making a wound that is sure to suppurate profusely, when a much more simple method, namely, that of including the scrotum in a plain clamp, can be more easily performed". He recommends, then, that when a hernia is present the intestine should be "returned into the abdomen, and the scrotum and its contents on the side of the hernia included in a strong wooden clamp (not a caustic clamp) placed as close to the external ring as possible, and the whole mass allowed to slough".
Fig. 118. - Inguinal Hernia.
A A, Intestine. B, Internal abdominal ring. C, Inguinal canal. D, Knuckle of intestine. E, Testicle, and F its enclosing sac.
While this destructive process is going on on one side of the instrument a constructive one is going on in the vicinity of the inguinal canal, where the structures above the clams are being united together, and the aperture closed against a recurrence of the mishap.
It is most important that measures should now be taken to prevent any recurrence of the accident. Before the animal returns to his stable provision should be made in the stall for raising the hind-quarters by under-packing with peat or straw, or both, so that the bowels may be inclined forward, and so directed away from the enlarged ring. Nothing but gruel should be given for the first twelve hours, and the diet for the subsequent forty-eight hours must contain but little solid matter. Bran scalded with linseed-tea or oatmeal-gruel, and given as sloppy mashes, is the most suitable aliment, to which may be added a little salt and malt meal.