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Oh

no! Its a big fat bitch spay Objectives


This lecture aims to provide practical tips and advice on how to safely perform neutering procedures and caesarian-section. I dont want to admit it but I hate doing spays! Ovariohysterectomy is considered a day one skill for veterinary graduates yet it is a relatively complex surgical procedure that has the same complications as other abdominal procedures. Retrospective studies demonstrate that the postoperative complication rates for ovariohysterectomy in both cats and dogs is potentially greater that 15%. An overall complication of 20% has been reported for veterinary students performing OHE under direct supervision in a teaching hospital (Burrow et al 2005). A consequence of this procedure being performed on a regular basis is an assumption that all veterinary surgeons should be able to perform an ovariohysterectomy with confidence, in a short period of time, through a small incision without any complications. Ironically it is likely that this attitude towards ovariohysterectomy probably influences the high complication rates seen in retrospective studies. Q. Do I need to discuss much with the owner a bitch before spaying? A. Owners have a tendency to book their pet in for a neutering procedure and assume they do not need to discuss this with you, the vet, because it is a routine surgery. However, at some stage prior to surgery a brief veterinary discussion needs to occur to enable them to give informed consent. Obviously you should not scare the owner and all the advantages of neutering need to be mentioned as well. Potential complications of spaying a bitch include: Seroma Wound breakdown or infection (< 5%) Haemorrhage Intermittent vaginal bleeding Ovarian remnant syndrome Uterine stump pyometra Uterine stump granuloma ( incontinence) Ligation of ureter ( endstage kidney or incontinence) Urinary incontinence due to urethral sphincter mechanism incompetence (USMI) Most complications can be avoided, for the vast part, by correct aseptic and surgical technique, as well as the owner complying with your postoperative care instructions. Seroma: Do not undermine the skin underneath your abdominal incision it is not necessary. Close the incision accurately and perform careful haemostasis. If you do get a seroma, drainage is not recommended it should resolve gradually without any intervention over 4 6 weeks. Fine needle aspiration (especially if repeated) can lead to abscessation due to inoculation with skin commensals.

Wound breakdown or infection: Ensure good aseptic technique, correct surgical technique (including suture selection and placement), and do not give antibiotics to routine neutering patients as these are clean surgeries and doing so can increase the risk of wound infection (including multidrug resistant wound infections). Discuss rest and avoiding self-trauma to wound with owners and use a buster collar as required. If you do get a wound infection, you will need to prescribe a course of antibiotics (ideally based on C&S), use open wound management and perform secondary closure if the wound is large once you have a healthy bed of granulation tissue. Haemorrhage: Usually poor ligature placement on ovarian or uterine arteries and/or failure to ligate large vessels in the broad ligament. More likely to occur with inadequate abdominal exposure. Ligate the uterine arteries individually as well as placing an encircling ligature around the cervix and ligate the broad ligament in mature or fat bitches. If haemorrhage is serious/deteriorating (ie. animal is in shock), re-explore the abdomen (stabilise shock first), make a large incision, use retractors and use the duodenal and colonic manoevres to locate and check the ovarian pedicles. Intermittent vaginal bleeding: This is due to erosion around uterine vessels underneath a ligature or infection of the ligature. Avoid a single ligature around uterine body ligate uterine arteries individually. If severe then perform exploratory laparotomy to re-resect uterine stump with ligation of individual uterine vessels and transfixing ligature of cervix. Ovarian remnant syndrome: This is due to failure to remove all ovarian tissue due to incorrect surgical technique. More likely to occur with inadequate abdominal exposure and more common in cats. Animal will show clinical signs of oestrus cycling and vaginal cytology at this time will be consistent with oestrus. Resolved by exploratory laparotomy and removal of ovarian tissue which is often (up to 50%) bilateral! Uterine stump pyometra: As for ovarian remnant syndrome with additional incomplete resection of uterine tissue, or incomplete resection of uterine tissue combined with exogenous source of progesterone. The uterine stump is re-resected as well as remnant ovarian tissue. Uterine stump granuloma: Caused by use of non absorbable sutures or other inappropriate sutures to ligate uterus, poor aseptic technique or excessive devitalised uterine tissue and can result in urinary incontinence. Requires exploratory laparotomy to resect affected tissue be careful of proximity and adhesions to bladder neck and ureters! Ligation of ureter: More likely to occur with inadequate abdominal exposure (and it is always a good idea to ensure the bladder is not full and expressing it manually if necessary whilst preparing the patient for surgery). Check carefully all the way around any ligature that you have not inadvertently included extra tissue before tying it down if you cant see all the way around the ligature then you need to improve your exposure!

Ureter ligation or trauma is most likely to occur when i) dealing with a dropped ovarian pedicle or ii) when ligating the cervix next to a distended bladder which is obscuring surgical visualisation and cranially displacing the trigone region. Ureteral obstruction hydronephrosis endstage kidney. Less commonly, inclusion of a ureter in a uterine ligature leads to erosion of the ureter and formation an acquired ureterovaginal fistula incontinence. Treatment of a ligated ureter is exploratory laparotomy and removal of ligature +/- re- implantation of the ureter (if less than 4 weeks) or ureteronephrectomy if end stage kidney. USMI: Overall, urinary incontinence is uncommon after OHE in bitches, @4-10%. The question of whether to spay before or after the first season is still controversial. Waiting to neuter until after the first season in at risk breeds e.g. Doberman, Old English Sheepdog, Weimaraner, Irish setter, Boxer or any other patient that already has urinary incontinence for whatever reason is advisable (50% of bitches with congenital (as apposed to acquired) USMI have resolution of incontinence after their first season. Resolve any obesity (urinary incontinence after spaying is more likely in heavier dogs) and decide on the merits of the various medical and surgical management options of for USMI. It is important to have mentioned this potential complication to owners prior to surgery, especially in at risk breeds. Note: Despite owners concern over this, OHE does NOT cause obesity. Q. How big should my incision be? A. The length of the incision is dependent on the size of the dog and should be made from cranial to the umbilicus and extended approximately 1/3 or greater of the distance to the pubis from the umbilicus. In cats, a midline incision should be positioned more caudally (middle third of the distance from the umbilicus to the pubis). See exploratory laparotomy lecture for tips on how to enter the abdominal cavity. A larger incision (if you perform a continuous suture pattern for closure) does not add significant surgical time and does not increase wound healing time at all. Q. How can I find the ovarian pedicle amongst all this fat? A. Two simple steps: 1. Make a bigger hole (+/- remove falciform fat) and use retractors. 2. Perform a duodenal manoeuvre for the right pedicle and a colonic manoeuvre for the left pedicle. Q. Could you please stop the bleeding? A. No problem: 1. Predict before the procedure which cases are going to potentially provide an increased surgical challenge, for example: obese animals (harder to identify and ligate pedicles) deep chested dogs (harder to elevate pedicles)

mature bitches that have had more than one oestrus (more likely to bleed from the broad ligament). For these dogs make a larger abdominal incision than usual from the outset and use abdominal retractors. This will allow you to fully expose the ovarian pedicles and hence allow easier access for your clamps and ligature placement. 2. If you encounter any problems during surgery in any patient, increase the exposure by making a bigger incision and using retractors. 3. Breakdown the suspensory ligament to ensure good exposure 4. Use the three clamp technique. 5. Consider a transfixing ligature for large ovarian pedicles. Use a sliding vascular knot to achieve a secure ligature when not performing transfixing ligatures. When applied correctly, a vascular knot is more secure than a surgeons (double throw) knot. 6. As you blunt dissect the broad ligament place haemostats on bleeding vessels and ligate if required. 7. Ligate the uterine artery on each side of the cervix before clamping / transecting and placing a transfixing ligature. 8. Consider doing an ovariectomy instead of an ovariohysterectomy. 9. Perform the duodenal and colonic manoevres to locate and check the ovarian pedicles. 10. If you are getting really stressed, take time out it is better to do nothing for a while than to blindly fish. Pack everything with swabs for a few minutes. Reposition your lights. Take a few deep breaths. Start again by improving your exposure using all the tips described above and if you can, ask nurse to scrub in. An animal will not bleed to death from an ovarian pedicle at a rapid rate. It will take less time to enlarge the incision, place retractors and ask someone to scrub in than to try to find a pedicle by blindly fishing. Blind fishing is also the way that really serious complications occur involving damage to important adjacent structures e.g. ureters. 11. Dont panic if your pedicle bleeds after ligature placement, just place another using all the tips described above. Place the second ligature directly over the top of the first ligature.

Q. How do I know it is not bleeding excessively? A. In the majority of cases, if you have a bleeding ovarian pedicle that requires attention, the blood will visibly well up from the abdominal cavity. Blood stains on a swab placed in the abdomen at the end of the procedure are not indicative of haemorrhage that needs attention. Perform the duodenal and colonic manoevres to visualize the ovarian pedicles directly before closure. Elevate bladder to check the uterine pedicle. Use suction or swabs

to remove blood around the ovarian pedicles and then it will be perfectly obvious if there is blood spurting out in a pulsatile rhythm from the pedicle it not a slow ooze that you have to wait for, if a ligature is too loose you will see haemorrhage pumping from the ovarian artery. Q. What is the risk of a stump pyometra occurring? A. Extremely low. For a stump pyometra to occur you have to leave remnants of both the uterus

and ovaries. It is more common in Europe to perform ovariectomy rather than ovariohysterectomy for sterilization of bitches. Practices in the UK are starting to offer clients the choice between these two procedures. The obvious benefit of ovariectomy for you as the surgeon is being able to position the incision cranial over the ovaries. In the cat the same applies. As a consequence you do not need

to be concerned if you do not remove the entire uterus, provided that you have removed both ovaries. Q. Which suture material should I use for ligation? A. Any of the modern synthetic absorbable sutures would be acceptable, although I probably wouldnt choose one of the very short lasting ones (e.g. Monocryl, Caprosyn). A multifilament (e.g. Vicryl, Dexon, Polysorb) is preferred by most surgeons for ligature use because of low memory/easy handling properties. Catgut can be used for ligatures but it loses knot security when it gets wet (it swells) so you need a minimum of four throws on the knot and promotes inflammation in the tissues around it. As a rule of thumb I put 4 throws on all ligatures regardless of the suture. Q. Cat spay flank versus midline approach? A. There is no reported difference in duration of surgery or complication rate in flank versus midline OHE in cats (Coe RJ et al 2006). However, one study found there was a tendency for cats spayed by a flank approach to be in more pain postoperatively (Burrow et al 2006). If the cat is pregnant or you have any other reason to believe the surgery may be more challenging a midline approach is preferable. It is much easier to extend a midline incision than a flank incision if a problem arises. Retractors are also helpful in cats, and if you dont have a small abdominal retractor, Weitlanders or even a pair of Gelpis may be used. Q. Dog castration closed or open approach? A. Both are acceptable. I usually perform a closed castration because there is less postoperative swelling with this technique. Lower the ligated pedicle before releasing it because you need to check for haemorrhage after tension on the pedicle has been reduced. Make sure skin sutures are not too tight as this is a common cause of postoperative discomfort in this area. Q. The dog castration I performed earlier on today has collapsed due to suspected postoperative haemorrhage how do I deal with this? A. The testicular pedicles retract back through the inguinal canals into the abdomen once they have been released at the pre-scrotal castration site. Therefore: 1. Scrotal swelling does not correlate with postoperative testicular artery haemorrhage 2. Testicular artery haemorrhage post-castration presents as progressive abdominal distension and shock. A peritoneal tap confirms the abdominal fluid is blood.

3. If a dog has serious/deteriorating haemorrhage (animal is in shock) post-castration then exploratory laparotomy to identify and re-ligate the bleeding testicular pedicle is required (stabilise shock first).

Caesarian Section
Q. How do I know a C-section is indicated? A. Perform a physical exam to check the bitch is pregnant and to look for any signs of illness, dehydration and toxicity. Perform a vaginal exam to look for a retained puppy, vaginal discharge and check for presence of Fergusons reflex (pressure against the vagina and cervix normally simulates strong uterine and abdominal contractions during labour). Ultrasound is useful to check the number of foetuses as well as foetal heart rates and movements (unviable foetuses are an obvious cause for C-section). 1. Obstructive dystocia: - Oversized, malpositioned or maldeveloped foetus - Small pelvic canal or pelvic fracture/trauma 2. Uterine inertia - Complete primary uterine inertia i.e. no second-stage labour (gestation > 70days) - Incomplete primary uterine inertia (i.e. second-stage starts but uterine contractions fail and are, or become, refractory to oxytocin: If the bitch is healthy and there is no evidence of obstructive dystocia administer oxytocin (2 units/kg IM, not exceeding 20 units). If there is no response after 45 minutes and there is still no distress another oxytocin dose may be given. If there is still no response after 45 minutes further medical therapy is unlikely to be helpful and a C-section is indicated. If healthy pups are born within 30 minutes of oxytocin, it can be repeated every 30 minutes as needed. Hypoglycaemia and hypocalcaemia is rare at this stage but should be checked for if there is no response to oxytocin. - Secondary uterine inertia i.e. uterine muscles become exhausted after prolonged contraction against obstruction or after efforts to expel large litter. This form is unresponsive to oxytocin and there is a lack of Ferguson reflex. C-section is indicated if there has been more than 30 minutes of strong unproductive straining, more than 2 hours of weak straining, or more than 4 hours since the birth of the last pup. 3. Foetal putrefaction 4. History of previous dystocia/C-section The prognosis for both dam and foetuses is good if surgery is performed within 12 hours of the onset of second stage labour. Neonate survival rates after surgical treatment of dystocia have been reported as 92% at birth, with 80% of pups still alive seven days after surgery. Tips for performing C-Section surgery: Prepare everything that you need for surgery and puppy rescuscitation before you induce anaesthesia to minimise anaesthetic time.

Q. Can I spay the bitch at the same time? A. Lactation and neonatal survival rates are not reported to be adversely affected by ovariohysterectomy compared to a conventional caesarean. If the owner requests concurrent spaying this can be done either before or after the hysterotomy - both have similar survivals for dam and neonates. En bloc ovariohysterectomy (ovarian and uterine pedicles isolated and clamped just prior to removal of the uterus with the foetuses) reduces surgical time which is useful in debilitated bitches or queens with dystocia, minimises abdominal contamination with uterine fluid and does not produce any problems associated with lactation. Disadvantages include the need for more nurses to resuscitate numerous neonates simultaneously and the quick time needed between clamping of the uterus to removal of neonates (30-60 seconds). Q. How do I open the uterus and remove the puppies? A. A ventral midline incision in the body is the best approach to the uterus. Milk the puppies out through the incision, rupture the amniotic sac, clamp and cut the umbilical cord and aseptically pass the puppy to an unscrubbed assistant. You do not need to remove the placenta if they are difficult to separate. Q. What closure should I use? A. Single or double layer closure, appositional or inverting using absorbable monofilament suture material. Give oxytocin if the uterus does not begin to involute or is bleeding excessively.

Clip as much as you can just prior to induction. Even when anaesthetised you may need to do some clipping in lateral recumbency because the weight of a gravid uterus when the bitch is put into dorsal recumbency may compress the diaphragm and/or vena cava and cause problems with respiration (reduced tidal volume) and blood pressure. Placing a folded up towel under the animal to elevate the cranial end may help relieve some of this pressure. Place an intravenous catheter and give crystalloid fluid therapy (10ml/kg/hr) to avoid hypotension and decreased foetal blood flow due to fluid loss and blood loss. Use the minimum amount (to effect as needed) of anaesthetic and all other drugs that depress the cardiovascular system. Drugs that depress the mother will also depress the foetuses. Use abdominal swabs to pack of the uterus from the rest of the abdominal cavity before performing the hysterotomy to minimise contamination from uterine fluids. An intradermal suture pattern, avoiding the need for skin sutures, is useful with respect to suckling puppies not having to negotiate skin sutures post-operatively. You may give intravenous prophylactic antibiotics as this is a clean-contaminated surgery. Postoperative antibiotics are not required unless an infection is present e.g. putrefaction of a dead puppy or other complicating factors. There is no actual evidence base to make decisions regarding non-steroidal anti- inflammatory drugs in lactating bitches after C-section (NSAID are contra-indicated in pregnant bitches and puppies < 6 weeks) but a single intravenous dose after surgery seems to have no obvious adverse affects on neonates (Mathews, KA 2008) Place the puppies with the bitch as soon as is practical.

References and further reading www.vets.tv/spay - 1hr spaying video on BVA website, inc. demonstration of vascular knot Burrow R, Batchelor D and Cripps P 2005: Complications observed during and after ovariohysterctomy of 142 bitches at a veterinary teaching hospital. Vet Rec 157, 829-833 Coe RJ, Grint NJ, Tivers MS et al 2006: Comparison of flank and midline approaches to the ovariohysterectomy of cats. Vet REc 159, 309-313 Burrow R, Wawra G, Pinchbeck G et al 2006: Prospective evaluation of postoperative pain in cats undergoing ovariohysterectomy by a midline or flank approach. Vet Rec 158, 657-661 Thrusfield MV, Muirhead RH and Holt PE 1998: Acquired urinary incontinence in bitches: its incidence and relationship to neutering practices. J Small Animal Practice 39, 559 Stocklin-Gautschi NM, Hassig M, Reichler IM, Hubler M, Arnold S 2001: The relationship of urinary incontinence to early spaying in bitches. J Reprod Fertil Suppl., 57:233-6.

Robbins MA, Mullen HS. En bloc ovariohysterectomy as a treatment for dystocia in dogs and cats. Vet Surg. 1994 Jan-Feb;23(1):48-52.

Mathews, KA 2008: Pain management for the pregnant, lactating and neonatal to paediatric dog and cat VCNA(SA) 38(6), 1291-1308

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