Fistulæ of the rumen and reticulum are difficult to close on account of their low position in the abdominal wall, but, if great care is exercised, they may be successfully treated. Those of the abomasum, on the contrary, only tend to increase in size, and any surgical interference still further favours the destructive action of the gastric juice. As a rule, therefore, they cannot be treated.
Fistulæ of the second variety comprise all intestinal fistulæ. They may be either accidental or artificial, and they are less grave than gastric fistulæ, because they are rarely situated in the lower portions of the abdomen. With time they may become closed either spontaneously or by means of simple treatment tending to regulate the passage of food through the bowel.
SECTION VII.
GENITO-URINARY REGIONS.
DISEASES OF THE URINARY APPARATUS.
Symptomatology. The urinary apparatus comprises the organs of secretion (the kidneys) and those of excretion (the ureters, the bladder, the urethra).
A thorough examination of the urinary apparatus should include, firstly, that of the external organs (the sheath, glans penis and urethra) in the male, and, in the female, the vulva, meatus and urethra; secondly, that of the internal organs (the bladder, ureters and kidneys) in both sexes.
To carry out the external examination, the head must first be fixed and the hind limbs hobbled. If necessary, the animal can be attached to the side of a wall.
External examination comprises inspection and palpation, which is only possible in males. Inspection will reveal at once the existence of malformation, deformity, traumatic lesions, or tumours of the organs.
By palpation the sheath and glans penis can be examined, and cellulitis, abscess formation, calculi in the urethra, obstruction of the extremity of the canal by very fine gravel, as in the case of sheep, etc., can be detected.
The inner margin of the right kidney may also be examined by external palpation, though only in very thin animals. The examination is made from the flank region, behind the last rib, in an upward direction and towards the right (Fig. 227). The kidney, attached under the lumbar region, sometimes extends back beyond the last rib, under the transverse processes of the lumbar vertebræ. On the left the presence of the rumen prevents any examination.