Genital Organs of the Bitch

The ovaries (Fig. ) are small, elongated-oval in outline, and flattened. Each ovary is situated close to or in contact with the posterior pole of the corresponding kidney, and thus lies ventral to the third or fourth lumbar vertebræ, or about half-way between the last rib and the crest of the ilium. Each is concealed in a peritoneal pouch, the bursa ovarii, which has a slit-like opening ventrally. The two folds which form this pouch contain a quantity of fat and unstriped muscle. They are continued to the cornu of the uterus, constituting the mesosalpinx and the ovarian ligament. The surface of the ovary presents prominences caused by projecting Graafian follicles. There is no distinct hilus.

The Fallopian or uterine tubes are small and average two or three inches (ca. 5 to 8 cm.) in length. Each passes at first forward and then turns backward, having a straight or only slightly flexuous course. The fimbriated extremity lies in the bursa ovarii, and has a rather large opening. The uterine orifice is very small.

The uterus has a very short body and two long narrow horns. In a bitch of medium size the body is about an inch (ca. 2 to 3 cm.) and the cornua five or six inches (ca. 12 to 15 cm.) long. The horns are of uniform diameter, are nearly straight, and lie entirely within the abdomen. They diverge from the body in the form of a V toward each kidney. Their posterior parts are united by the peritoneum. The neck is very short and is fused dorsally with the vagina. It has a thick muscular coat. The mucous membrane of the uterus has long uterine glands and also short tubular crypts.

The broad ligaments contain fat and unstriped muscle. They are much longer in the middle than at either end. The posterior part is attached to the anterior part of the vagina. The round ligaments are very long, extending through the inguinal canals, and traceable almost to the vulva.

The horns of the gravid uterus present dilatations or ampullæ, which contain the fœtuses, and are separated by constrictions. The gravid uterus lies on the ventral abdominal wall, and toward the end of gestation extends forward to the stomach and liver.

The vagina is relatively long. It is narrow anteriorly, and has no distinct fornix. The muscular coat is thick and consists chiefly of circular fibers. The mucous membrane forms longitudinal folds. The canals of Gartner are usually absent.

The vulva has thick labia which form a pointed inferior commissure. The mucous lining is smooth. On either side of the urethral orifice there is a small depression. The glandulæ vestibulares majores are absent, but the smaller glands are present, and their ducts open ventrally on either side of a median ridge. The vestibular bulbs are relatively large and join dorsally. The clitoris has a small pointed glans, beneath which is a diverticulum. The corpus cavernosum is a little more than an inch (ca. 3 to 4 cm.) long in a subject of medium size, and is infiltrated with fat.

The mammary glands are usually ten in number, and are arranged in two series extending from the posterior part of the pectoral region to the inguinal region; they are, therefore, designated according to location as pectoral, abdominal, and inguinal. The teats are short, and present on their apices six to twelve small orifices of the excretory ducts.