health centre for cats
“the fresh approach to veterinary care”

All images and text© Copyright of Jaffa’s Health Centre for Cats. Sed vulputate

Why do we castrate our dogs?

And why are we commenting on dog procedures?

The commonest disease I see in dogs is obesity, with the majority of dogs overweight. Many are already on 'light' diets or prescription weight-loss foods. Few successfully lose weight and keep slim. Hardest of all to control are castrated male dogs, especially breeds such as labradors.

Whilst I have great issues with most ‘weight-loss’ diets, the simple answer would be to avoid castrating dogs in the first place. Yes, un-castrated (entire) dogs can still get overweight, but much less readily, and they are easier to slim if they do get a bit podgey. However a heavy castrated labrador can be a nightmare to slim down.

So why do we vets recommend castration? And isn't it the socially responsible thing to neuter your dog?

It’s the responsible thing to do?

Well I refuse to castrate my own dogs without good reason, and I don’t consider myself to be an irresponsible owner, no matter what the RSPCA mantra dictates. Entire (non-castrated) dogs don’t produce puppies unless given the opportunity - that is where the responsible ownership comes in.

Keep your entire male dog under proper control and it will not create unwanted puppies, period! Equally, bitches don’t get mated unintentionally unless allowed to roam (provided of course that you don’t have an entire dog in the household). The responsible dog owner keeps their pet under control at all times, whether or not it has been castrated/speyed.

So what about the cancers we are going to prevent?

Unlike the female of the species, malignant cancers of male dogs are rare. Prostate cancer is very rare indeed, though commonly we see 'old man' prostatic hypertrophy - enlargement of the prostate gland due to too many years of testosterone coursing through our veins. However, if this occurs, we can simply castrate and cure! Testicular cancers are usually no more of a problem - testicles are readily examined, and if the worst happens, again castration can be performed.

Do we chop bits off ourselves in case they develop disease? Of course not - so why should our pets be any different? If dogs are left entire, there is nothing to stop one getting them castrated should disease or problems develop. Indeed, I half-castrated one of my own dogs at 14yrs old  due to a testicular growth - and then took the other testicle away at 16 yrs old because he kept on getting over-amorous with his toy rabbit, getting his willy stuck out! (we buried him curled up around blue bunny!)

Latest research has also shown that castration of certain breeds of dog can lead to a very significant increase in the risk of them developing certain cancers – so we may actually be causing cancers rather than preventing them!


Castrated dogs are better supposedly behaved! - but are they? If a dog is aggressive towards other male dogs, then castration will reduce this. If it is aggressive due to fear then castration may make it worse - often the boldness provided by testosterone is the dog's crutch - take it away and his fear becomes greater.

Breed and type of dog does influence aggression. But rather than using this as justification for castration, maybe we should be considering the type of dog we are breeding !

So how about bitches?

This may seem hypocritical, but I am all for speying bitches. In practice, this does prevent unwanted litters, and has much greater sociological benefits to the overall dog population.

Imagine a population of 10 male dogs running free with 10 bitches. The result would be 10 litters twice a year ie 20 litters. If all but one dog was castrated, the result would still be 20 litters a year. If all but one bitch were speyed, the result would be 2 litters a year!

Other reasons in favour of speying bitches

Walking a bitch in season in public upsets every male dog in the vicinity, and housing an entire male and female together is a nightmare for 3 weeks twice-yearly. Ovarian cancer, though quite rare, is not readily detected - you cannot just palpate the ovaries as you can with a dog's testicles. There is also a massive reduction in mammary (breast) cancer when bitches are speyed young. If done before their first season, the risk is 100th that of an entire bitch. Between first and second seasons the risk is 1/10th. 2nd to 3rd season it's halved, and after the third season there is no sparing effect. So the moral is that if you are going to have your bitch speyed, get it done young!

Incidentally I don’t really hold with the argument that you spey them to stop womb infections (pyometra) as this is generally, if expensively, remedied in most cases by surgery should it occur. However, elimination of the risk is never-the-less a benefit.

I do agree that this is all a matter of opinion. Every pet should be considered individually including the personal circumstances of the owner - and every owner should have accurate information regarding the pros and cons.

Which is why the routine recommendation of neutering of either sex should be a considered opinion rather than a blanket recommendation.


Cats are different! Cats are not naturally sociable animals, and the way we force large numbers of cats to share limited territory is asking for trouble! In the wild individual cats would each have territories much larger than the houses and gardens that most of us possess.

Unlike dogs, who sort out social their structure and usually end up overcoming minor differences, cats adopt a confrontational attitude when subjected to high population densities. Territory-challenged cats therefore end up in regular fights. Not only do cats teeth carry nasty bacteria, but cat bites are an effective way of spreading the nasty cat viruses such as FeLV (Feline Leukemia) & FIV (feline AIDS). An entire tom usually becomes a battle-scarred creature with a chronically scarred face from sparring wounds.

And female cats, unlike their canine counterparts, cannot be kept under control if they are allowed out of the house.

So I am all for speying and castrating cats for their (and our own) convenience and health. However, if you have a male housecat that you wish to keep entire, I will not try and pursuade you otherwise.

Why are we commenting on dogs as well as cats?

Because I feel it needs saying, and because I see obese dogs on every dog walk I take.

And because obesity has such serious health consequences.

If you see a lean labrador, check to see if it has been castrated - I bet it hasn’t!