Page 490 - WSAVA2018
P. 490

 25-28 September, 2018 | Singapore
secondary hydroureter, ovarian remnant syndrome with or without secondary uterine stump inflammation (Table n° 1). Incidence of these conditions varies depending on OVX or OVH from 7% to 27% in the bitch and 33% in the queen. There is no correlation between incidence of complications and age of the animal, ability of the veterinarian or presence of reproductive diseases. There is no breed predisposition. The complication observed most frequently seems to be (vaginal or intra-abdominal) haemorrhage, which is much more common in large (80% incidence) as opposed to
small (20% incidence) size bitches. Vulvar blood loss may occur following OVH (blood coming from the uterine pedicle, the suspensory ligament or the broad ligament) as well as following OVX (blood coming from the ovarian pedicle). Some complications may
be due to the stage of the reproductive cycle in which spaying is performed: intraoperative bleeding is more common during proestrus and estrus (due to high estrogen concentrations) while false pregnancy may follow when spaying is performed during diestrus (due to rising prolactin concentrations following an sudden progesterone fall).
Table n° 1 – Short- or long-term complications due to ovariectomy (OVX) or ovariohysterectomy (OVH) in bitches and queens. Based on personal experience
and data from literature (a): total number of short- and long-term complications; (b): haemorrhage of the uterine or ovarian pedicle becaude of incomplete ligature or ruptrue of blood vessels). (*) the risk of complications is higher following OVH than OVX.
Heat after gonadectomy in bitches and queens is a well know surgical complication of both OVX/OVH. Ovarian remnants are more commonly found on the right side, and may (but this is not proven) occur more frequently following OVH than OVX because of the fact that the abdominal incision tends to be more caudal in OVH therefore making it more difficult to reach the ovaries. Ureteral obstruction, due to the inclusion of the ureter into the ligature, or the development of a uretero-vaginal fistula are reported only following OVH. Granulomas of the ovarian (less common) or uterine (more common) pedicle may be due to the use of non-absorbable
suture material, while inflammation of the uterine pedicle may occur if the most caudal part of the uterus is accidentally caught in the suture during OVH performed
for a presenting complaint of pyometra. Pyometra may develop following OVX if an ovarian remnant is left in place and the bitch/queen resumes regular cycling following surgery, or if progestins are administered for medical reasons later in life.
Anesthetic and surgical issues for early-age patients
Early age patients should be in healthy conditions and normally hydrated before anesthesia and surgery. Also, proper immunization for the most common infectious diseases should have been previously performed. Although vaccination should be a prerequisite, vaccination failures may occur and death of immunized young dogs/cats entering a veterinary facility for castration purposes has been reported during the 7-day period following surgery. From a surgical point of view, neutering at a very early age is a very simple and quick, low-risk procedure. The incidence of short-term post- surgical complications is lower in young (<12 weeks of age) than in young adult (>24 weeks of age) animals and most of the complications are minor problems
such as swelling of the abdominal suture. The following guidelines should be followed when performing surgical procedures in very young animals:
• In order to avoid hypoglycaemia fasting prior to surgery should not be longer than 1 hour; also, eating should be allowed as soon as the patient is able to stand
• The use of heating pads and a warm environment during and after surgery is recommended in order to avoid hypothermia which occurs very commonly in young patients; hypothermia prolongs recovery time and slows the metabolism of anesthetic drugs
• Controlling post-operative pain is fundamental to help return to normality thereby stimulating appetite. Anti- inflammatory drugs are know to cause physeal cartilage damage following chronic use, but they may not be harmful following (although there is no information about side effects due to single treatments)
• The opioid petidine provides analgesia and sedation without causing bradycardia; petidine must be given exclusively IM because releases histamine causing pain when given IV
• Avoid bradycardia-inducing drugs (such as alpha- agonists like medetomidine)
• Avoid long-acting drugs (such as acepromazine or tiletamine-zolazepam) as they prolong recovery time
• Use short-acting drugs for induction of anesthesia (such as propofol or alfaxalone) to avoid drug residues during the recovery phase
• Benzodiazepine can be used to increase sedation (thanks to its cardiovascular sparing effect)
• If possible use only volatile anesthesia during surgery

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