Desexing: It’s bad for vizslas, too

Spay/Neuter is bad for Vizslas

Late last year, a study was published looking at the incidence of cancer in desexed golden retrievers, finding a correlation between earlier desexing (before one year old) and certain types of cancer.

Now, in February, there is a new study supporting many of the findings in the golden retriever study, but this time looking at the incidence of cancers in Hungarian Vizslas. As behavioural disorders are also common in the breed, the researchers decided to look at the impact of desexing on these disorders, as well.


While we will look at their findings in more detail, the main take home points from this research are (quote):

“revealed that gonadectomized dogs had significantly higher odds than did sexually intact dogs of having mast cell tumour, hemangiosarcoma, lymphoma or lymphosarcoma, all other cancers, all types of cancer combined or behavioral disorders, regardless of the age at which the dog was gonadectomzied. The 2 exceptions were that male dogs gonadectomized at [less than or equal to] 12 months of age did not have a higher risk of developing hemangiosarcoma and dogs gonadectomized at > 6 months of age did not have a higher risk of developing a behavioural disorder, other than fear of storms.”

And it is important to note that the age of onset was earlier for all cancers and disorders when the dog was desexed.

So now that has wet your appetite, we will look at the research in more detail.


About the Study

This was a retrospective cohort study – meaning it was a piece of research based on events that had happened over time, looking back at that time.

The study included 2,505 vizslas born between 1992 and 2008. Of them:

  • 604 of the vizslas had cancer(s),
  • 648 had behavioural disorders,
  • 1,421 of them were desexed,
  • 362 vizslas were desexed at 6 months or earlier (209 of these were female, and 153 of these were male),
  • 298 vizslas were desexed at 7-12 months (157 were female, 141 were male), and
  • 711 vizslas were desexed at 12 months (459 females, 312 males).

Data for this study was collected from an online survey conducted during 2008, which targeted vizsla owners to partake by advertising through breed clubs, email lists, websites, magazines, and newsletters.  75% of respondents were involved with Vizsla breed clubs, so it was a biased sample.

Participants came from 25 countries in all, including the US, UK, Canada, and Australia.

This study was designed to consider age of desexing and its effects, so the owners were asked to identify when their dog was desexed, or if it was not at all. It’s important to note that many studies simply look at ‘entire’ or ‘desexed’ and don’t look at lifetime exposure to gonads – this is one of few in a new study of research actually considering the time of desexing.



An earlier Vizsla Health Survey found that cancer, especially hemangiosarcoma and lymphoma, “was listed as the most common cause of death in the breed.”  Desexing was associated with the development of these cancers, according to their survey, and also associated with the development of behavioural disorders.

This is no surprise, as numerous studies have linked desexed with various types of cancer, including hemangiosarcoma, but also prostate cancer, transitional cell carcinoma, and osteosarcoma.

This research show that a desexed vizsla was 5 times as likely to have cancer (other than mast cell cancer, hemangiosarcoma, or lymphoma or lymphosarcoma) than vizslas that were entire.

Not only were desexed dogs more likely to get cancer, but the earlier they were desexed, the earlier they were diagnosed with cancer.

All in all, dogs desexed at any age were more likely to have cancer than dogs not desexed.

Interestingly, though, “There was no significant difference in the longevity of gonadectomized Vizslas, compared with the longevity for those that remained sexually intact”. This means that even though desexed dogs were more likely to get cancer, and sooner, this didn’t seem to make them die younger.



When it comes to hemangioarcoma, desexed females were 9 times as likely to get hemangiosarcoma than entire females.

For males, males neutered after 12 months of age had a higher risk of developing hemangiosarcoma.

The research makes note that this is not a ‘one off’ event: “Of concern, studies have found an increased risk of hemangiosarcoma, a common tumour that frequently leads to fatal outcomes, in gonadectomized dogs, which is in concurrence with findings for the present study.” That means that vizslas are not alone in being more likely to develop hemangiosarcoma when desexed, especially when it comes to bitches.


Mast Cell Cancer

Desexed vizslas got mast cell cancer at a significantly higher rate (3.5 times more likely) than entire dogs, and they got diagnosed with this cancer sooner than entire dogs.



While there was no difference between females and males in the likelihood of developing lymphoma or lymphosarcoma, desexed vizslas were significantly more likely (4.3 times as high incidence) entire.


Mammary Cancer

There is some evidence that bitches left entire for longer are more likely to develop mammary cancer. However, this study says, “authors of a recent systematic review of all reports in peer-reviewed journals on the associations among neutering, age at neutering, and mammary gland tumours concluded that the evidence that neutering reduces the risk of mammary gland neoplasia is weak and not a sound basis for firm recommendations on neutering because of limited evidence and bias in published results”.  We can, at least, say there is some debate on the correlation of mammary cancers and desexing.

In regard to this study, mammary cancer was not common. There were 1,360 female dogs in the study, with 535 of them being entire, and only 11 developed mammary tumours. That is, 2% of entire bitches got breast cancer. (The authors of this study also note that 10 of those 11 bitches were desexed at later than 5 years old.)

This equates to only .4% of the dogs in the 2505 strong study developed mammary cancer. In comparison, 11% of the 2505 dogs in the study having mast cell cancer, hemosarcoma, lymphoma, or lymphosarcoma.Considering this, community emphasis on mammary cancer seems misguided as it is not biggest concern, especially in this breed.


Behavioural Disorders

There have been studies that have shown a correlation between gonadectomy and behavioural problems, but whether these affects on behaviour are ‘good’ or ‘bad’ is a matter of debate, with different studies showing different things.

The Vizsla Health Survey found that behavioural problems were prevalent in the breed, hence the focus of this study on behavioural problems. These types of behviour problems were mostly fear, anxiety, and increased arousal.

This study did something clever though: Dogs who had a behavioural problem before desexing were excluded from the analysis. The logic? “Excluding dogs that might have been gonadectomized because of a behavioural problem eliminated a confounding factor that could have incorrectly suggested a stronger association between gonadectomy and behavioural problems.”

Desexed vizslas were more likely to have behavioural problems than sexually intact dogs, and dogs desexed at or before 6 months had a 1.8 times higher incidence of behavioural disorders than sexually intact dogs. These behavioural problems included: fear of storms, separation anxiety, fear of noises, fear of gunfire, timidity, excitability, submissive urination, aggression, hyperactivity, and fear biting.

As with cancer, the younger the dog was at time of desexing, the earlier a behavioural problem was diagnosed.

Fear of storms was particularly significant. Desexed dogs were 4.1 times more likely to be scared of storms than entire dogs. Bitches were more likely to be scared of storms than males – but males desexed younger was more likely to be scared of storms earlier. (Desexing time didn’t change when females became fearful of storms.)

The author notes, “It should be mentioned that the most common behavioral problems in Vizslas in this study did not include sexual behaviours (eg, mounting and urine marking).”


Why is it so?

Briefly, this study predicted that sex steroids such as estrogen, progesterone, and testosterone is related to immunity, especially the surveillance for cancer cells. That is, without gonads to produce sex hormones, the immune system does not function as normal.



To me, the most important points from this study are:

  • There seems to be no compelling reason to desex Vizslas in regard to that individual dog’s health or temperament, on the basis of this study.
  • Desexing does not inevitably result in a healthier and more temperamentally stable dog.
  • As orthopaedic problems are not common in Vizslas, this study does not consider joint disorders and desexing, as other studies have.
  • Despite the incidence of cancer in neutered dogs, this study suggests that desexed and intact Vizslas live about the same length of time.
  • Vets need to discuss the pros and cons of desexing with clients.


Further Research Discussion

This kind of research is just the beginning! Further research can consider:

  • Are Vizslas special? We need to do this type of research in other breeds.
  • For all studies considering affects of desexing, age of desexing should be considered in the data collected. There are very few studies looking at life-long gonad exposure, and so conclusions on optimum age of desexing is hard to make.
  • Biological effects of removing gonads.
  • Sterilisation for dogs without gonadectomy – like vasectomies or hysterectomies (leaving ovaries).
  • Something that I have been considering for a while,” An additional potential source of confounding was that behavioural differences between sexually intact and gonadectomized dogs could have been attributable to being subjected to hospitalisation and survey at a young age, rather than to the hormonal changes conferred by gonadectomy. A prospective, randomised blinded study with a control (sham) surgery could be performed to distinguish between these 2 scenarios.”
  • More research on gonadectomies, on cancer, and on behaviour, and how they’re connected.



Zink MC, Farhoody P, Elser SE, Ruffini LD, Gibbons TA, & Rieger RH (2014). Evaluation of the risk and age of onset of cancer and behavioral disorders in gonadectomized Vizslas. Journal of the American Veterinary Medical Association, 244 (3), 309-19 PMID: 24432963

Read the study here.


Image Credit: Thanks to klam101 on DeviantArt.


Further Reading:

Why would you NOT desex your dog???

Is desexing a cult?

Golden Retrievers: Cancer if you do, cancer if you don’t

DON’T Spay or Neuter Your Pets

New Research That Raises Questions About Neutering Recommendations


Predicting Adults from Puppies – in 15 Minutes!

A typical vet consult is just 15 minutes. Is this long enough for a vet to diagnose future behavioural problems in puppies? Vaccination consults seem to be an ideal time for vets to assess puppies and make recommendations for the future, but is it really enough time for a vet to reach adequate conclusions?  Pageat set out to find out.

Listen to audio:

Or read on…

Rottweiler puppy on vet table having a check up.


256 puppies were observed during a vaccination appointment at the vet.  The puppy was first allowed to ‘free range’ around the room, and then the puppy was examined. The behaviour of puppies during this consult was noted.  The owner was also asked to answer 8 questions (on fear, sleep, and self control).

Pageat wondered if the behaviours shown by the puppies and the answers given by their owner might have a correlation between the behaviour (including problem behaviour) the puppy may have as an adult.

Telephone consults occurred 1 month after the vaccination consult, then 6 months after, and then another evaluation was done when the dog came in for its vaccination 1 year afterwards.

Pageat found that there was a correlation, and referred to 6 classifications for adult dogs: ‘normal’, deprivation syndrome, hypersensitivity-hyperactivity, disorder of sensory homeostasis, phobia, and separation anxiety.

This preliminary study showed that there was some merit to Pageat’s ideas. Below are the behaviour classifications that Pageat created and how they correlate to the behaviours and questionnaire responses seen in puppyhood.


Normal Dogs

Pups that were likely to have a ‘normal development’, unsurprisingly, displayed normal behaviours in the vet clinic, like:

  • sought comfort from their owner,
  • checked out the room while ocassionally checking in with the owner or vet,
  • sought vet’s contact,
  • had submissive posture when vet reached over the puppy, and
  • sometimes cried when restrained, but soon settled.
  • On the questionnaire, owners said there were no fears, no sleep problems, and no excessive biting.

So: Puppies that act normally in the vet seem to act normally as adults.


Deprivation Syndrome

‘Deprivation syndrome’ is the term that Pageat used, which means dogs that are under socialised and so fearful of most things, which in turn leads to fear aggression. (source)

In the vet consult, pups were more likely to grow up with deprivation syndrome if they:

  • were stationary (didn’t move around the exam room),
  • reacted fearfully when touched by the vet,
  • remained fearful even when the owner interacted with them,
  • persistantly tried to escape and bite from restraint, and.
  • if they appeared to calm when restrained, they started fighting again when the restraint was lessened.
  • The owner’s responses to the questionnaire described the puppy as ‘fearful’ towards loud noises, moving objects, and people.

That is: puppies that acted fearful during the 15 minute vet consult will probably stay fearful. They should immediately start an intensive socialisation program to try to reduce their fearful reactions.


Hypersensitivity-Hyperactivity Syndrome

‘Hypersensitivity-hyperactivity syndrome’ is basically a dog with lack of control, especially bite inhibition. They are often not-aggressive but nonetheless hurt their owners and others because of their lack of bite inhibition in ‘over the top’ play.

In the vet consult, pups were more likely to grow up with this syndrome if they:

  • were active, ran everywhere,
  • repeatedly interacted with ‘every thing’ they could in the exam room,
  • if this interaction included chewing and often destroying items,
  • immediately started to play during the physical exam,
  • growled and bit,
  • tried to escape restraint by biting, urinating, or defecating, and if this fighting may continue for 30 seconds or more,
  • had an owner who’s presence didn’t influence the puppy’s behaviour, and
  • had an owner who was covered in bites themselves.
  • Owners on the questionnaire indicated the puppy didn’t sleep solidly (i.e. made noise at night) and described the puppy as rough or bitey when playing.

That is: Puppies who seemed hyperactive and orally fixated would stay that way into adulthood. Puppies in this category should be put in puppy playgroups and otherwise taught to inhibit their bite.


Disorder of Sensory Homeostasis

This was the most confusing classification that Pageat used. Here are a couple of definitions I was able to come up with in regard to ‘sensory homeostasis’:

  • “the ability to react in a suitable manner to sensory stimulations coming from the external environment” (source)
  • “The normal state can be regarded as the normosensoperceptive [normal sensory perceptive] condition to be maintained in the physiological range by means of various cooperative and coordinated mechanisms” (source)

That is, ‘dealing with’ (behaviourally, psychologically, and physically) the environment in a normal way. So, a dog who has ‘sensory homeostasis’ could be described as ‘a dog that reacts suitably to sensory input from its environment’.

The behaviours of puppies in this group were diverse:

  • Puppies were active, running everywhere and chewing everything – or they did the opposite, staying in one place resting and not moving much.
  • Puppies either began to play when you interacted with them, or just stayed still.
  • These puppies bit when they were restrained – sometimes with urinating and defecating as well, but always did not submit.
  • The owners reported these puppies were fearful, that they didn’t sleep well or were active, and they were rough biting and playful.

As you can see, there is a lot of variety in this category, and I’m not sure what conclusions can actually be reached. This is especially true when you compare with the rather logical and conclusive results made under different headings.


Phobic Adult Dogs

Dogs were more likely to be fearful adults if they were puppies that:

  • sought comfort from owners in new environments,
  • if the explored, they checked in with the owner or vet as exploring,
  • adopted a submissive posture during handling,
  • cried softly during restraint, or
  • moved legs when restrained, but soon calms down and is submissive.

That is, the pups that overall seemed quite soft and ‘submissive’ and sought reassurance from people were likely to be fearful dogs in adulthood.  These puppies could also have their behaviour remedied by socialisation where they could learn to be more outgoing (as they realise the world is a not-so-scary place).


Separation Anxiety

Separation anxiety is basically a fear of being alone.  Pups that exhibited the following behaviours were more likely to have separation anxiety as an adult:

  • rests as close as possible to the place it was left,
  • vet has to initate contact, and
  • pup exhibits fearful behaviours like escaping, biting, urinating, defecating or anal sac excretion, but when the owner approaches, these behaviours stops.
  • The owner answered ‘yes’ to fearful behaivours on the questionnaire.

A vet could recommend that puppies displaying these behaviours begin to engage in a separation anxiety program before issues become apparent. Undertaking anti-separation anxiety procedures are good practice, anyway, but could be applied with more emphasis in puppies like this.



Unfortunately, this research is almost 10 years old and hasn’t been as revolutionary as first hoped.  However, it shows there is still promise in the original suggestion:  Vets could have a role in preventing problem behaviours from developing or becoming more pronounced by making recommendations based on behaviours seen in a 15 minute consult.  Vets are a major source of information for dog owners, including new puppy owners, and almost all puppies will visit a vet for at least their first vaccination. Because of this, it’s vital that we make the most of these consults and direct puppy buyers to appropriate resources.


Links of Interest

Resources for New Puppy Owners

How to Stop Puppy Biting




Pageat, P 2004, ‘Evaluating the quality of behavor development in puppies: preliminary results of a new scale’, Proceedings of the 10th European Congress on Companion Animal Behavioural Medicine.