In spay-neuter clinics, ovariohysterectomy (OH) is the surgical procedure carried out on female dogs in order to address population control. It is also regarded as a routine elective procedure in veterinary practice to prevent future pregnancies. In addition, it may also be indicated for gynaecological or for medical reasons , for example, diabetes or epilepsy, in order to prevent hormonal changes from modifying the response to treatment.
Although this is regarded as 'routine', this procedure should NOT be under-estimated. It involves opening the abdominal cavity, and the ligation and securing of major blood vessels. A surgeon must therefore be competent as well as confident in undertaking this procedure, or else be supervised by an experienced veterinary surgeon.
This surgery can be approached through the midline or via the flank. At our ITCs, we routinely use the midline approach and advocate this technique for routine surgeries.
Timing of surgery
There are many considerations when deciding on the optimal time for neutering, for example, the effects on incidence of reproductive neoplasia, urinary tract disorders, non-reproductive neoplasias, developmental and growth factors and behaviour. There are also significant breed differences. A recent review of the literature concluded that the timing for canine spaying is not so well defined, but that life-threatening diseases, such as mammary neoplasia and pyometra, should be considered a major factors1. Although the likelihood of mammary neoplasia increases in a bitch after each oestrus (with no reduction in incidence of this condition in animals spayed after 2 1/2 years old), the conclusions suggests that female dogs should, ideally, not be spayed until they are 3-4 months of age in order to avoid the risk of urinary incontinence. However, it may be necessary to spay female dogs earlier than this in some spay-neuter clinic situations.
Early neutering e.g. 8 to 12 weeks, is advocated by many shelters and re-homing organisations. With early-age spaying, the increased risk of urinary incontinence may be accepted after a risk-benefit analysis, dependent on local situations, resources and other factors.
Midline approach
The midline approach is a commonly used approach for dogs and one that we advocate at our International Training Centres.
Advantages
Visualisation of organs. There is good exposure to abdomen which facilitates identification of abdominal contents including the ovaries, as well as bleeding pedicles which require re-ligation.
Easy extension of the incision. It is simple to extend the abdominal incision for improved access, if required.
Optimal choice for pregnancy/pyometra. It is the optimal approach of choice for heavily-pregnant bitches, or for pyometra.
Reduced tissue trauma due to the incision being made in the fibrous, linea alba.
Risk of suture breakdown in minimal when the surgeon is trained in good suturing technique, uses appropriate suture material, and performs surgery professionally.
Disadvantages
Risk of herniation. If suturing is not performed competently, there is a higher risk for herniation. It is important that the correct suture material, and the correct suturing and knot-tying techniques are used to minimise this risk.
The next article will describe the process of OH using a midline surgical approach.