the remarkable reproductive success of this species is a major factor in the ability of cats to colonise diverse environments .
the onset of puberty in females can be as early as 12 weeks and a single female cat can produce 40 kittens per year .
it is estimated that between 75% and 97% of cats in a population need to be desexed to stabilise numbers .
early - age desexing removes the responsibility for desexing from owners who , despite financial incentives , frequently fail to return the cat for surgery , while still allowing rehoming at a young age to optimise socialisation .
there is increasing evidence that early - age desexing is not only safe in the short and long term , but also offers advantages , including reduced surgical time and rapid recovery , over the traditional age of 6 months or older .
many national and international shelter , welfare and veterinary organisations now endorse early - age desexing , including the royal society of the prevention of cruelty to animals , the international society of feline medicine and the american veterinary medical association . despite these factors , recent surveys indicate that attitudes within the veterinary profession towards early - age desexing are variable .
the choice of surgical approach to ovariohysterectomy ( ohe ) shows regional variation , with a flank approach favoured in the uk ( 96% ) , and a midline approach in the us .
benefits described for midline ohe include better visualisation and reduced postoperative pain scores , whereas a flank approach may offer shorter surgery time and reduced risk of hypothermia , herniation or evisceration .
evidence to support one approach over the other is limited , particularly in prepubertal cats .
the aim of this study was to determine whether there was an association between age and surgical approach , individually or combined , and perioperative wound complication in cats undergoing ohe .
cases were recruited from the cat protection society ( cps ) of new south wales desexing program .
surgeries were performed at four veterinary clinics ( a  d ) . a single surgical approach , either flank ( clinic a ) or midline ( clinics b  d ) was used at each location .
only healthy cats with a body weight of 1 kg or more were accepted in this program .
cats were examined twice daily and findings , including wound assessment , were recorded in a manual database .
the database was searched retrospectively to identify cats that underwent ohe between 1 june 2010 and 31 december 2012 inclusive .
cases were included if the following information was available : age at the time of surgery ; clinic where surgery was performed ; and complete records from at least 1 day prior to surgery to 5 days postsurgery inclusive .
cases were excluded if surgery was performed by a veterinary student under the supervision of a veterinarian .
a wound complication was recorded when the description of the surgical site included any of the following terms : redness ; swelling ; heat ; pain ; exudation ( grouped as inflammation ) ; or wound dehiscence in the 5 day postoperative period .
data were exported into a csv file and analysed using statulator , an online statistical program ( http://statulator.com/ ) .
initially , descriptive analyses were conducted , including the creation of frequency tables for categorical variables and the calculation of summary statistics for age to understand the distribution of variables . to evaluate the association of age with wound complication
, cats were classified into groups according to age : those aged 12 weeks and those aged > 12 weeks .
contingency tables of age and surgical approach with wound complication ( yes / no ) were created and  analyses were conducted to evaluate crude associations between them .
stratified analyses were then conducted to evaluate association of surgical approach with wound complication after adjusting for age .
, 194 were excluded because the clinic was not identified ( n = 145 ) , recording of wound status was incomplete ( n = 45 ) or surgery was performed by a student under supervision ( n = 4 ) . in total , 312 cases met the inclusion criteria ( table 1 ) .
the mean age at the time of surgery was 41 weeks ( median 12 weeks , range 5468 weeks ) .
wound complication was identified in 19 cases ( 6.09% ) . in 18 of these , signs were consistent with inflammation at the surgical site , while wound dehiscence was identified in a single 12-week - old patient that had an ohe via a midline approach .
age at desexing was not a risk factor for wound complication ; there was no significant difference in the development of wound complications in cats up to 12 weeks of age compared with older cats ( p = 0.38 ) ( table 2 ) .
considering all cases , regardless of age , a midline approach was associated with 2.95-fold increased risk of wound complication compared with a flank approach ( p = 0.011 ) . when a stratified analysis by age was performed ( table 3 ) ,
a midline approach was 4.59-times more likely than a flank approach to result in wound complication in cats up to 12 weeks of age ( p = 0.015 ) .
however , in cases over 12 weeks of age , there was no association between surgical approach and the risk of wound complication ( p = 0.22 ) .
frequency tables of categorical variables  and odds ratios based on crude association of each explanatory variable with development of wound complication ci = confidence interval stratified analysis of association between surgical approach and wound complications , after adjusting for age adjusted risk ratio and 95% confidence interval ( ci ) 2.75 ( 1.186.43 ) ; cochran  mantel  haenszel statistic 5.80 ; p value 0.016
we used a cut - off of 12 weeks to ensure that cats were prepubertal ; of 33 cats < 1 year of age that were pregnant at desexing in a uk study , two were < 4 months old .
others have demonstrated that early - age desexing from 6 weeks of age carries no increased risks to the patient .
there are several factors that require particular attention when performing ohe in paediatric patients compared with older cats .
these include avoiding hypoglycaemia by fasting for a much shorter period ( 34 h ) and offering food immediately on recovery , as well as preventing hypothermia .
a comprehensive review of early - age desexing , including suitable anaesthetic protocols , has recently been published .
the overall incidence of perioperative wound inflammation ( 6% ) or dehiscence ( < 0.003% ) in this study was low , as expected for a routine procedure performed in healthy animals .
our findings support previous studies that demonstrate no increase in the short - term complication rate following the desexing of young cats compared with older cats .
in fact , higher overall complication rates are reported in cats > 6 months compared with those aged < 12 weeks .
previous prospective , randomised studies comparing flank vs midline approaches to ohe have produced conflicting results and none have investigated prepubertal patients specifically . some of the suggested pros and cons of a flank vs a midline approach to ohe may become redundant when they are applied to prepubertal patients .
for example , reduced abdominal and bursal fat allows enhanced visualisation and more accurate vessel haemostasis during ohe by either approach in kittens .
the observation here that a midline approach increased the risk of wound complication in cats up to 12 weeks , but not in older cats , is interesting .
the first , investigating ovariectomy in 38 cats of any age , found that a midline approach carried a higher risk of wound swelling , while a flank approach was more painful on palpation .
a second study of 66 cats aged 6 months to 10 years found a greater risk of wound tenderness and discharge with a flank compared with a midline approach .
surgeries were performed by veterinary students and the overall wound complication rate , as reported by owners , was high ( 42% ) with severe complications noted only after midline surgery . in a separate study ,
burrow et al compared flank and midline approaches to ohe in 20 cats ( median age 10 months ) performed by a single experienced surgeon and found that the flank approach was marginally quicker but was associated with a tendency to be more painful than a midline approach .
it is important to note that kittens are less likely than adult cats to demonstrate visual indicators of pain , so early - age desexing protocols should include interactive pain assessment such as wound palpation .
a flank approach was used by a single clinic so we can not exclude that factors other than approach contributed to our observations .
however , the overall wound complication rate was low and ohe is a standard procedure so any effect from other factors is suggested to be low .
these findings add to the evidence base supporting a cultural change to embrace the practice of early - age desexing as standard for feline patients .
 objectivesthe aim of the study was to investigate the effects of age and/or surgical approach on perioperative wound complication following ovariohysterectomy ( ohe).methodsa retrospective search of perioperative monitoring records from a shelter desexing program was conducted to identify cats that underwent ohe between 1 june 2010 and 31 december 2012 inclusive . 
 a wound complication was defined as gross observation of inflammation or wound dehiscence at the surgical site in the 5 day postoperative period . 
 cases were grouped according to age ( 12 weeks or > 12 weeks ) and surgical approach ( flank or midline ) . 
 stratified analyses were conducted to evaluate the association between surgical approach and wound complications , after adjusting for age . 
 mantel  
 haenszel adjusted risk ratio , cochran  mantel  
 haenszel test statistic and their 95% confidence intervals were presented.resultsa total of 312 cases met the study criteria . 
 the overall wound complication risk was low ( 6.09% ) and was not related to age . 
 a midline approach was associated with a 4.59-times increased risk of wound complication , compared with a flank approach in cats up to 12 weeks of age ( p = 0.015 ) but not in older cats.conclusions and relevancethese findings support the practice of prepubertal desexing for cats . 
Introduction
Materials and methods
Results
Discussion
Conclusions