Neutering Kittens
Emma Stevenson MA VetMB MRCVS
Veterinary Surgeon
RSPCA Greater Manchester Animal Hospital
Overview
Why neuter cats? Why prior to puberty? The technical bit What about afterwards?
• Population control
– Animal welfare
– Public health
– Environmental
The importance of neutering
• Individual animal
– Reduce disease
– More agreeable pets for rehoming
The importance of neutering
Disease prevention
Mammary neoplasia Ovarian neoplasia Uterine neoplasia Pyometra (8% mortality)
Castration reduces mortality
Road traffic accidents FIV and FeLV Cat bite abscesses
Owned cats >90% owners neuter eventually But 20% have a litter, of which 75% unplanned
>10% of owned elective
cat spays unplanned pregnant 36% of relinquished animals
from unplanned litters
Pregnancy percentage of total monthly cat spays
0
5
10
15
20
25
30
35
40
Owned cats Strays
% p
reg
na
nt
Jan 2012 Jan 2013 Jan 2014
Why neuter prior to puberty?
Population control Shelter space Disease prevention Surgical reasons
Cat spay prior to puberty
Small blood vessels Minimal abdominal fat Predictable anatomy
– Not in oestrus
– Non pregnant
– No pyometra..
When to neuter different populations
Feral cats Shelter cats Owned (charity)
When? Anytime (>300g)
Before adoption
Before puberty
Why? Difficult to recapture
Lack of shelter spacePoor uptake post-adoption
High risk of pregnancy
Anaesthetic considerations
• Selection of candidates
• Age v weight chart
• BSA dosing
• Minimise stress
Anaesthetic Considerations
Hypothermia Hypoglycaemia Cardiovascular Hepatic function Renal function Rapid recovery
'QUAD' Anaesthetic Protocol
Weight (kg) Body Surface area (m²)
Volume of each drug (ml)
0.5 0.06 0.04
1.0 0.10 0.06
1.5 0.13 0.08
2.0 0.17 0.10
Anaesthetic agent Dose
Medetomidine 600 μg/m²
Ketamine 60 mg/m²
Buprenorphine 180 μg/m²
Midazolam 3 mg/m²
Analgesia
Analgesia after feline OVH comparing buprenorphine
or butorphanol, and carprofen or meloxicam, 2012,
J Feline Med Surg, Polson, Taylor & Yates
100 cats, blinded, randomised prospective study All had midazolam-medetomidine-ketamine
anaesthetic All 4 groups- low pain scores, no significant
differences No differences amongst kittens or pregnant cats
Alternative analgesia
Butorphanol Buprenorphine Methadone
Surgical Considerations (spay)
Surgical Considerations (Castration)
Prenatal testicular descent
Delay cryptorchids Standard technique Care with traction BP fold and no
spines
Long term consequences?
Long term outcome of gonadectomy performed at an early age or traditional age in cats, JAVMA, 2000, Howe
Cohort, 263 shelter cats, 3 year follow up Not increase in short term morbidity or mortality No increase in infectious disease, behavioural or
other medical problems (incl FLUTD)
Long term consequences?
Obesity Multifactorial Neutering a risk factor But this is not an inevitable
consequence of neutering!
FLUTD No correlation between
castration and urethral diameter
Diabetes mellitus
Delayed growth plate closure
Conclusions
Low complication
rate v benefit to
individual
Overpopulation is a major welfare issue
Limited evidence base
Mammary neoplasia
Obesity
Overcrowded shelters
Pyometra
Which anaesthetic protocol?