Neutering – Not So Neutral

Vet Dr Nick Thompson talks us through his view on Neutering

In the 1980s I started vet school in 1986. At college in Edinburgh, like all the vet schools at the time, we were taught that neutering (castrating male dogs and cats and spaying females) was sensible, safe and kept the kitten and puppy population down. 

This may have been true in the 1980s, but the world has moved on, and I’m not so sure that our perception of neutering has kept up.

Neutering in Europe

For example, in Germany and Sweden, it is now illegal, or at the very least frowned upon, to neuter any male or female dog unless there is a medical necessity.  

Whenever I go to France or Spain, I see entire male dogs left, right and centre! 

Then and Now

In the 1980s, roads were less busy, and the pace of life in towns all over the UK was arguably a little less frenetic. Suppose you go back to the 1950s, even more so. In those days, we commonly saw dogs wandering about. 

Nowadays, one rarely sees stray dogs. No, I’m not saying they don’t stray anymore, but we live more insular, controlled lives where our neighbours, whom we may not know, would be only too happy to dob us in for allowing our dog to wander the streets. 

Neutering was more of a necessity then than it is now because of this more closed, controlled world in which we now live. 

Early Neutering 

In this blog, we’re not talking about the early-neutering of rescue animals and certain breeds, sometimes as young as six weeks. That is an entirely separate issue, but I’ll give you a spoiler alert – I think it’s wrong. We’re also not going to discuss laparoscopic neutering of females (it’s good) or ovary-sparing spaying of females (also a good thing, but you need to do your homework). Those are for another blog, another day. 

Advantages of Neutering in the First 1-2 Years

The advantages of neutering females at this time are that it reduces the chance of getting mammary tumours, eliminates the risk of pyometra, and stops them from having puppies or kittens and usually (not always!) gives you a more placid pet. 

Queens are usually neutered in the first 6m of life. Bitches are best neutered between the first and second season if you decide to do it. 

The advantage of neutering (castrating) males is it eliminates the problem of testicular cancer (pretty rare), reduces the chance of prostate problems in later life (pretty common), usually (!) makes for a less challenging dog and usually eliminates dangerous (running under buses in search of bitches in season) or annoying (humping your leg) behaviours. 

Disadvantages of Neutering in the first 1-2 Years 


Some females dogs (about 15%) may get mild to severe urinary incontinence (dribbling) at some point after spaying. Often it’s in later life but can be two weeks after the spay. Many spayed bitches put on weight after spaying, and it can be challenging to control for life.

Female dogs are more prone to immune-mediated disorders like atopic dermatitis, autoimmune haemolytic anaemia, Addison’s Disease, hypothyroidism, immune-mediated thrombocytopenia and IBD.  


Weight gain is the main problem with male cats and dogs. It doesn’t happen with all, but most, and you can be creating a problem for life. 

Problems Post Neutering with Both Sexes

Being overweight can predispose to cruciate ligament rupture, hip dysplasia, diabetes and hypothyroidism. Joint disorders in dogs neutered under 12 month of age can increase by up to four times. 

Neutering German Shepherd Dogs can increase the chance of hip dysplasia, cruciate disease and elbow dysplasia by up to three times entire dogs. 

Neutering increases the chance of getting osteosarcoma bone cancer in large dogs, especially Rotties and reduces longevity in this breed. It increases the chance of getting a number of cancers in a number of breeds. 


It’s all a bit confusing, really. 

If you want my overview of the whole picture, then I’ll say these points: 

  • You don’t have to neuter all dogs and bitches no matter what anymore. The world has changed.
  • It would seem there might be a slight advantage to neutering female dogs between the first and second season but see the caveats above. 
  • It would seem there might be a slight advantage to leaving male dogs entire unless their behaviour is a problem. 
  • Neutering is not a guarantee to calm a nervous, anxious or aggressive dog. It can make them worse. 
  • We tend to neuter most of our cats still at about six months of age. 
  • Overall, we must consider breed, intended use, financial considerations, and life situation when deciding on neutering decisions. 
  • For an individually owned animal living in a home, decisions should be based primarily on factors that impact that animal’s individual health and the health and wellbeing of that household, and secondarily on population control. 
About the author

Nick Thompson is a vet. He has been fighting for responsible, species-appropriate raw food feeding for pets for 25 years. His tireless drive for healthy pets from birth to graceful old age brought him to raw feeding in the mid-1990s.
Nick is Founding President of the international Raw Feeding Veterinary Society ( and has co-authored a pioneering worldwide survey of 79 vets and their experiences feeding raw food. He has co-organised international raw food conferences for the RFVS since 2012.
In 1999, Nick established his specialist practice, Holisticvet ( Now based in Corsham, near Bath, he offers homeopathy, natural nutrition and herbal medicine and a lot of good old-fashioned common sense for dogs and horses.
His pet topics are gastroenterology and the microbiome and the misuse of pharmaceuticals in medicine. He loves researching all aspects of human and animal nutrition.
Nick also shares his passion for raw feeding with a nutritional consultancy service to the premier raw pet food companies in the UK and Europe. He has lectured and consulted in Raw Food, Nutrition and Medicine throughout the UK, Eire, Northern Ireland, Finland, Spain, Portugal, France, Germany, the Czech Republic, Belgium and the Netherlands.
Nick is embracing Social Media to spread his message: Facebook: Holisticvet Ltd; FB Public Figure: Dr Nick Thompson; Instagram: holisticvetuk.
Nick is married to Elly and has two children, Arthur and Ophelia, and lives in Wiltshire, UK with chickens a Snowshoe cat called Ziggy and a Whippet-Italian Greyhound cross (mongrel), Bluebell.
When not trying to convert the world to a species-appropriate diet, Nick runs barefoot, swims and eating real food. Not all at the same time.

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