In dogs or cats with flaccid walls of the abdomen external manipulation may detect in the kidneys, differences in size, position, and tenderness as well as the presence of tumors. The distended bladder also may be distinctly felt, and the pyriform area of flatness on percussion will serve to map out its size and outline.
In the horse the urethra is superficial and easily traced over the ischiatic arch and for some distance downward, when it becomes deeper and is less easily felt. In the bull the urethra is deep over the ischiatic arch but becomes more superficial lower down and can be easily felt at the sigmoid flexure and below. In sheep and dog it is easily followed from the ischium to the end of the penis.
As a rule the penis is easily drawn from its sheath in the horse and dog; this is more difficult in the sheep and goat and still more so in the bull and boar. In the small animal protrusion is favored by setting him on his rump, with his back between the operator’s legs, and the pelvis doubled forward toward the sternum. The penis of the bull may be extended in presence of a cow in heat, and promptly seized, or it may be seized through the sheath back of its first bulging part and skillfully worked out. In the ruminant, calculi may be felt at the sigmoid curve, and in the ram, in the vermiform appendix at the fore end of the penis.
Internal Exploration. This is accomplished in the larger animals with the oiled hand in the rectum, the nails having been pared short and even to avoid injury to the mucosa. In ponies and yearlings the kidney may be felt, and this may be true also of mature animals of larger species in cases of hypertrophy or floating kidney. The ureters, bladder and intrapelvic urethra are easily felt in the male. The empty bladder lies on the anterior border of the pelvis; when full, it projects forward into the abdomen but retains its pyriform or, in the very young animal, its fusiform shape. In the female the sensation is somewhat modified by the presence on its upper surface of the uterus dividing into its two horns anteriorly. The single enlarged horn of pregnancy is especially misleading.
The female urethra, cervix and bladder may be explored through the vagina. To explore the cervix vesicæ and urethra the fingers are slowly drawn back from the bladder along the median line of the floor of the vagina. In the mare the cervix and adjacent portion of the bladder can be further explored with the index finger introduced through the opening of the urethra in the floor of the pelvis and at the junction of the vagina and vulva. In the cow the urethra is too small to be readily explored from within, and the orifice is still further guarded by the two lateral blind canals of Gærtner, into which the unskilled fingers more readily pass. Success only attends the careful search for the small central lower orifice. In the smaller animals the finger only can be introduced into vagina or rectum and the urethra, cervix and bladder only can be felt. The result of such exploration is straining even in healthy conditions but which becomes excessive in nephritis, pyelitis, renal, urethral, vesical or urethral calculus, cystitis, rectitis or enteritis.
The ureters are tender when inflamed, and they are swollen in calculus obstruction with an elastic feeling in front of the stone.
The bladder is very sensitive when overdistended, inflamed or pendent on the abdominal floor, or when the seat of calculus. In the absence of any liquid contents a calculus is felt as a hard solid mass firmly clasped by the contracted vesical walls. If liquid is present the solid hard calculus is felt movable in the fluid. An empty contracted bladder is firm and pyriform. An empty flaccid bladder, resulting from rupture or exhaustion, is flabby, with indefinite form and, if the seat of a lesion, tender. It varies in consistency with neoplasms (papilloma, sarcoma, carcinoma, or epithelioma). These have not the free mobility of the calculus floating in urine, and their point of connection with the wall may often be made out. When a solid body is felt, or suspected to be in the contracted bladder, an injection of sterilized water will usually facilitate diagnosis, and a differentiation of calculus and neoplasm.
Hypertrophy of the prostate is felt as a swelling of uneven outline over the cervix vesicæ. It is to be looked for especially in old dogs.
Urethritis is indicated by swelling and tenderness along the median line of the pelvic floor, back of the cervix. With a calculus in the urethra the swelling is more strictly localized and the canal in front of it may be full and elastic.