Risk factors
Multiple studies investigating the prevalence of FIV have identified several recurrent risk factors . A study of infection rates in UK shelters found that male cats were more likely to test positive for FIV than their female counterparts [ 4 ] , with age also found to be a risk factor . These results are reflected in similar studies elsewhere in the world [ 17 ] . However , in the current literature , there is little discussion about the effect of neuter status on infection rates . This could be due to the high prevalence of entire animals in the stray population , resulting in neuter status not being considered as an influential factor .
Several studies have linked cats with a history of bite wounds to higher rates of FIV infection [ 18 ] , with penetrative biting now believed to be the main route of transmission [ 10 ] . Aggressive behaviour , including factors that could increase this behaviour , could therefore be associated with a higher risk of infection . Entire male cats have been found to be more likely than neutered male and female cats to display aggressive behaviour [ 19 ] , placing them at higher risk of bite wounds .
A study conducted during a ‘ trap , neuter , release ’ project in New York found a decline in aggressive behaviour after neutering [ 20 ] , as reported by residents in the study area . A similar project was also carried out in Italy [ 21 ] , investigating the effect of neuter status on behaviour in a stray cat colony . All cats displayed a substantial decrease in aggression and an increase in more submissive behaviour compared with pre-neutering behaviour [ 21 ] .
A study in Brazil monitoring the activity of a group of stray cats before and after surgical castration [ 22 ] found a decrease in each cat ' s home range and area of activity ; this reduced the overlapping of cat territories and subsequent social interactions ( Figure 2 ).
Methods
Ethics
Permission to access the stray cat archives of RSPCA Finsbury Park Animal Hospital in north London ( then known as RSPCA Harmsworth Memorial Hospital ) was obtained from the hospital ' s clinical veterinary director .
Prior to data collection , ethical approval was granted by Edinburgh Napier University ' s Ethics Committee .
Data collection
Only cats under the direct care and legal ownership of the RSPCA hospital were included in this study . Owned pets were excluded from the study . All information was derived from documents filed under ‘ Stray Cat Archives 2019 ’ and checked against online records held by RSPCA Finsbury Park Animal Hospital . The collected data were stored in a password-protected Microsoft Excel spreadsheet . Data consisted of the following categories :
• date of cat ' s admission
• RSPCA hospital reference number
• whether the patient was dead on arrival
• sex of the cat
• cat ' s neuter status
• cat ' s FIV status
• cat ' s FeLV status
• cat ' s presenting condition , reason for admission or reason for inspectorate call
• outcome , if any .
Figure 2 . Neutering a male cat can reduce its tendency to roam , thereby reducing the overlapping of territories and social interactions .
34 Veterinary Nursing Journal