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Using early neutering to control unwanted litters
  1. M. Roberts1 and
  2. J. Clements2
  1. 1BVM&S, MRCVS, Director of Veterinary Services Cats Protection, National Cat Centre, Chelwood Gate, Haywards Heath RH17 7TT UK
  2. 2RVN, Neutering Manager, Cats Protection, National Cat Centre, Chelwood Gate, Haywards Heath RH17 7TT UK
  1. e-mail: Maggie.Roberts{at}

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MANY of us in the UK are relieved at this time of year as the days lengthen, our serotonin levels rise and spring is in full bloom. But at animal shelters across the country, staff are preparing themselves for their busiest time of year – kitten season – with the accompanying and inevitable infectious disease outbreaks. Although there are pockets where extensive neutering is making a significant difference to the cat population, most charities are once again overwhelmed by the numbers and lack the capacity to take all the unwanted cats into care. It is thought that more than 150,000 cats and kittens go through registered charities each year (Stavisky and others 2012), but this is likely to be an underestimate as there are many individuals involved in animal rescue and veterinary practices who undertake significant pro-bono work on unidentified feline patients.

Cats Protection, the UK's largest cat welfare charity, runs the largest single species neutering scheme in the world, having assisted in the neutering of more than 160,000 cats last year. Despite the huge number of cats neutered in the UK, there are still waiting lists at most rehoming charities (Stavisky and others 2012). Murray and others (2009) found that, although over 90 per cent of cats over six months of age are neutered, a fifth has at least one litter before neutering and 71 per cent of those litters are unplanned. Only 66 per cent of cats between the ages of six to 12 months are neutered. More recent figures from the Pet Food Manufacturers' Association concur with this. As cats frequently reach puberty at four months, it is logical that routine gonadectomy should be performed no later than this age to have an impact on the population without resorting to the much more unpalatable option of culling. Pre-pubertal gonadectomy (PPG), also known as ‘early’ or the more favoured ‘kitten’ neutering, has been carried out in the USA and Australia among other countries for several decades and in the past few years welfare charities have been encouraging vets in the UK to follow suit.

Murray and others (2008) showed that many UK vets were concerned about surgical and anaesthetic complications and the risk of long-term complications after PPG. There are several studies in existence that show that there are no significant differences in risk between PPG and neutering at the more traditional age of six months or older (Joyce and Yates 2011). However, it is right that there should be a strong evidence base for changes in veterinary procedures including elective ones such as gonadectomy. This is why the paper by Porters and colleagues (2015), summarised on page 572 of this issue of the Veterinary Record, is a valuable addition to our knowledge base.

The study they describe is part of a large-scale project funded by the Belgian Government, which is obviously more forward thinking than our own politicians who seem to have little interest in companion animals and leave such matters to non-governmental organisations. It is a prospective study comparing the relationship between the age of gonadectomy and health issues in shelter cats, both in the short and longer term. Its conclusions are consistent with many other studies: there is no evidence that pre-pubertal gonadectomy strategies in shelter cats are associated with short or longer term health problems. The cats were followed up until they were two years of age and there is certainly a need for further studies following up cats for much longer periods, ideally for their lifetimes, to add to existing literature. The more robust the evidence base, the more confident vets will be to embrace the procedure in paediatric patients.

Providing data on the health issues relating to PPG is the key for it being accepted as a tool to manage population control. Porters and others' study shows that the majority of the mortality and morbidity in the cats were related to infectious disease such as feline parvovirus before homing, and infectious disease and trauma such as road traffic accidents after homing, whatever the age of gonadectomy. It demonstrates how it is imperative to make every effort to operate on healthy kittens and to control infectious disease where possible through health checking, parasite control, vaccination and minimising stress.

Cats Protection's experience is that many vets will perform PPG on shelter cats but are still unwilling to carry it out on client-owned animals. Although this is likely to reflect some of the anxiety around PPG and the perceived lower value of shelter cats, this seems illogical from a clinical perspective. Kittens presented to shelters are likely be in poorer body condition or have a significant parasite burden in comparison to owned kittens, and the risk of contracting infectious disease is undoubtedly higher. If the procedure is safe for shelter cats, then it seems the risks would be the same or potentially lower for owned cats. It would be an interesting study to compare the two groups. Generally, four months is an acceptable age to neuter owned cats, whereas there are additional advantages to shelters in neutering earlier than this; the majority of their residents are neutered before homing and feral cats that are trapped can be neutered at any age rather than the alternative high risk strategy of releasing them and hoping to be able to trap them again in the future.

As there is a significant fluidity between the feral, stray, community and owned cat populations, it is important that timely neutering is performed in all of these groups of cats both to control the population and for the health benefits for the individual. Community cats are living in densely populated urban areas across the UK; they mix with pet cats and are much loved by many residents. The importance of neutering these cats early for their health and welfare is obvious and this also highlights the importance of not mixing the educational messages for the public, making four months the norm and not the exception for all types of cats.

Many cat owners are largely unaware of the reproductive capacity of cats (Welsh and others 2013) and this poor owner knowledge contributes to the high proportion of accidental litters, which may be as high as 85 per cent according to RSPCA's Tackling the Cat Crisis report (2014). Many owners who seem to have the best of intentions may not get round to making the neutering appointment for their cat at six months and this delay results in unwanted kittens being born. If four months of age is seen as standard, any delays in getting the procedure done will hopefully mean pet cats are neutered by six months at the latest, thereby preventing accidental litters.

Male kittens undergoing early neutering at a Cats Protection site at the start of this year's ‘kitten season’

A number of charities are working together under the umbrella of the Cat Population Control Group to maximise the effectiveness of cat neutering through collaboration on research, joint projects and coordination of activities. They have been working on providing resources for vets who are currently undertaking PPG or who are proposing to, in the form of a microsite of Cats Protection's website. Their ‘Early Neutering Register’ has been rebranded as the Kitten Neutering Database (or KiND) and provides technical information and scientific references as well as the database and the opportunity for practices to become ‘kitten neutering champions’. Peer-to-peer support and mentoring can help those veterinary surgeons and practices who would like to neuter younger cats, but would value the advice of a colleague before embarking on this path. Those signed up as champions can be found at

The veterinary profession is usually keen to embrace diagnostic tests, therapies and surgical techniques as long as there is evidence of their efficacy. This improves the service they give to their clients and patients and hopefully improves the profitability of the practice. However, veterinary advances should not help only those animals that have loving and financially secure owners. A Cats Protection survey showed that over 90 per cent of companion animal practices in the UK undertake some work for charities and the unowned population are a significant part of their clientele. Shelter medicine is a specialty in the USA and is now becoming a distinct discipline in the UK, with the first shelter medicine stream at BSAVA congress this year, the recent formation of the Association of Charity Vets and a BSAVA manual on the subject in the pipeline.

If animal welfare is at the heart of our profession, we should embrace techniques such as PPG for the benefit of the individual and the feline population whether they are owned, stray or feral cats.


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