Flank vs. Midline Approach to Neutering Female Cats

This article was contributed by Cathy Baxter of Kyashii Orientals.

This decision is a typical dilemma faced by those wishing to exhibit female neuters. Naturally owners want what is in the best interest of the welfare of their cat, but the potential for  changes to fur colour and/or the development of white hairs at the site of the surgery are also important considerations for the owners of show neuters that may need to be taken into account. However, while a flank spay is by far the most frequently undertaken female neutering procedure in the UK (up to 96% of all cat spays performed in the UK), in most other parts of the world cat spays are traditionally undertaken through a midline approach.

Historically, a flank spay has been preferred to ensure better (and more rapid) wound healing and thus a reduced risk of wound breakdown and complications such as infection and hernias at the incision site. However, the advent of modern suture materials would now appear to negate that perceived risk.In addition to this, from published data, a flank approach may give a slightly shorter total surgical time and therefore anaesthetic risk, but the difference is not great and averages out (in experienced hands) at approximately 1.5 minutes.

With better access to the abdomen, the midline approach may actually be associated with fewer complications, e.g. inadvertent tying and/or cutting of a ureter (the tube conveying urine from the kidney to the bladder). Ovarian remnant syndrome, where a fragment of ovarian tissue remains after the spay procedure and continues to produce hormones causing a cat to call and/or develop mammary hyperplasia, is a relatively uncommon complication following cat spays. However, there is no data on whether there may be a greater risk of this with flank spays, i.e. whether flank spays have an increased risk of leaving some residual ovarian tissue.

A midline spay can be useful for cats that are in season and may have a uterus that is more prone to bleeding  and for pregnant cats or cats being spayed to treat a pyometra. When dealing with a cat that is difficult to handle, a flank spay may permit somewhat easier postoperative monitoring of the surgical site when checking for potential complications.

Although studies are limited, current evidence clearly indicates that a midline spay may be associated with less postoperative pain than a flank spay and this maybe an important consideration. This could be as a result of fewer pain receptors in the midline body wall and skin and/or movement of the flank muscles at the incision site causing pain.While the choice of technique itself (flank vs. midline) may influence the degree of postoperative pain, the skill of the veterinary surgeon is likely to be an even more important factor. However, further research is needed, particularly into the issue of postoperative pain because if further studies consistently show reduced pain associated with the midline procedure, this may affect UK recommendations in the future.

Regardless of the approach(flank vs. midline), subjectively young cats appear to suffer less pain when spayed compared with older cats, and appear to return to normal behaviour more rapidly. Specific studies evaluating this are lacking at present, but this would be a valuable area of future research as perhaps pain perception is different in young animals. Nevertheless, good pain relief is still required for a cat spay, whatever the age of the cat.  For most routine neutering a single injection of pain killers during the procedure would provide sufficient pain relief, but each case should be assessed and treated individually.

From a behavioural aspect, when neutering young kittens (early neutering), there is value in allowing the kittens from a litter to share the same cage and to recover together in the same cage.

Conclusion

Despite neutering being one of the most common veterinary procedures, questions still remain about what constitutes best practice. Although there is some evidence that a midline spay may be less painful than a flank spay the success of the procedure  is likely to be highly dependent on the skill and experience of the veterinary surgeon, who in the UK will almost inevitably be more experienced in undertaking flank spays than using a midline approach.