Page 487 - WSAVA2018
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S. Romagnoli1
1Department of Animal Medicine, Production and Health, University of Padova, Agripolis, Legnaro, 35020 (PD), Italy
Gonadectomy is the surgical removal of both gonads under general anesthesia. In the female, gonadectomy (or spaying) is generally performed through removal
of both ovaries (ovariectomy = OVX) or of ovaries and uterus (ovariohysterectomy = OVH) via an abdominal approach. Whether or not bitches and queens should be spayed, what is the best surgical procedure and what is the best age to perform it are issues which have many welfare implications, as well as advantages and disadvantages. Prepubertal gonadectomy is commonly performed on immature male and female animals aging from 6-to-14 weeks and has been routinely used at many shelter and academic institutions in United States and Europe over the last quarter of a century to control pet over-population. Although regarded as a safe technique, prepuberal gonadectomy may carry some health concerns. Postpuberal gonadectomy still offer several advantages if performed early in life although the growth of reproductive organs and the potential presence of pathologic conditions may occasionally complicate the surgical approach. Also, the well known advantage
due to a reduced risk of mammary neoplasia is often considerably reduced when gonadectomy is delayed beyond the third cycle in bitches and queens.
Surgical technique – The midline incision should be done in the cranial third of the abdomen for bitches (ovaries are more difficult to exteriorize than the uterine body) and in the middle third of the abdomen for queens (uterine body more difficult to exteriorize than the ovaries). The length of the incision may be increased depending on uterine conditions (an enlarged uterus normally requires a longer incision). Once the ovary
has been located the proper ligament is clamped and the ovary is pulled up. When pulling up the ovary the ovarian suspensory ligament is stretched and may be simply broken with the index finger. A hole is made in the mesovarium avoiding the ovarian vessels (normally caudal to the vessels), then 2 or 3 clamps are placed on the ovarian pedicle. An incision is made between the 2 clamps (or – if 3 clamps are used - between the clamp closest to the ovary and the adjacent one), the ovary is removed and the pedicle is ligated directly below the remaining clamp (in case of a young bitch or queen) or the third clamp (the one most distant from the ovary) is removed and the ligature is placed in the groove caused
by the clamp. Removal of the ovary can also be done without using clamps but simply having the surgeon holding firmly the ovary and an operator ligate proximal to the ovary.
To remove the uterus the broad ligament is exteriorized, inspected and severed with the thumb or index finger,
or is ligated if highly vascularized. Once all potential sources of broad ligament bleeding have been eliminated (2 or better) 3 clamps are placed on the most caudal aspect of the uterine body which is then severed between the proximal and middle clamp. The uterine stump is ligated with a single ligature (for queens or small bitches) or a ligature is placed on each uterine artery. The caudal clamp is released and the remaining groove is used to facilitate placing the ligature on the uterine body. Resection of the uterine body can also be done without using clamps but simply having the surgeon hold firmly the uterine body and an operator ligate distal to the uterine body. The uterine stump is grasped with a hemostat and the clamp is released while checking for absence of bleeding, after which the uterine stump is replaced into the abdomen. Suture material is normally absorbable.
Ovariectomy vs Ovariohysterectomy - Whether to remove only the ovaries or also the uterus is for many veterinarians a true dilemma. The “Anglo-Saxon” or “British” school of thought has always had the approach of removing everything based on the concept that what is removed cannot cause a disease, while the “Latin” approach has always been that of removing only the ovaries since the uterus quickly undergoes atrophy following OVX, and perhaps the risk of developing urinary incontinence could be lower because of anatomical reasons. Research done in Utrecht in which 138 OVH’ed bitches and 126 OVX’ed bitches were followed up for 8-11 years, has clearly showed that between the 2 groups of dogs: a) there is no difference in short-term as well as long-term surgical complications; b) there is no difference in incidence of cystic endometrial hyperplasia, pyometra or any other uterine disease; c) there is no difference in incidence of urinary incontinence1
As a matter of fact, the only differences between the two approaches are the degree of invasiveness and length of the surgery, and therefore length of anesthesia, all
of which are higher in the case of OVH. This causes
a higher risk of surgical complications and a a higher stress for the animal as well as a higher cost for the owner. The following conclusion of Okkens et al.1 “There is no indications to remove also the uterus in elective castration procedures of healthy bitches, and therefore ovariectomy is to be considered the procedure of choice” is currently shared by the majority of US as
well as European authors2,3,4. Therefore, it is currently considered unethical to perform ovariohysterectomy
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