Thoughts on Kooikerhondje Temperament

Recently, someone new to the breed argued with me when I said I appreciated my dogs because unlike many Kooikers, they weren’t nasty. Perhaps “nasty” was the wrong word but the statement was more about my appreciation of my own dogs’ temperament than anything else, but it triggered some positive discussion. To my slight horror, for many respondents, my statement was the first they had heard of poor temperaments in Kooikers, although many had privately been struggling with their reactive dogs without speaking up, believing them to be abnormal or a personal failure. These were puppy owners that had somehow managed to get a dog of a breed they clearly did not understand and while I am not laying blame, we all agreed that temperament is not discussed as honestly in this breed as it should be. Temperament is so little understood in this breed that the nuance between “normal” and “abnormal” is often lost.

There are MANY Kooikers with poor temperaments. By “poor temperaments” I mean unsociability, reactivity or fear aggression, and/or true aggression towards dogs and/or humans. Some of these are easier to work around or train than others, of course, but if any breeder or enthusiast doesn’t recognize that temperament issues are a huge problem in the breed – they are either misinformed or purposely misleading someone. In the Clubregister, the international recording of data about every individual born, there are notations about temperament issues when the owners and/or breeders report it. The VHNK (Dutch Kooiker Club) publishes a quarterly newsletter that includes recently-deceased dogs and their cause of death, and it can be seen that at least annually one dog is euthanized for temperament issues. Assuming many or most cases of difficult dogs are never reported (whether or not they are ultimately euthanized) one can see that it is a significant issue, especially when underreported due to feelings of guilt or avoiding slander or an attempt to preserve one’s breeding business. Anecdotally, the breed community is aware of individuals and lines that display aggression at unacceptable levels.

But Kooikers are not the easiest or most well-understood breed – so how do we improve both education and temperament? At the 2017 VHNK seminar, it was discussed that perhaps temperament should be the topic of the still-COVID-delayed 2020 seminar, but until then, here are my thoughts.

Behavioral Problem or Kooiker?

The first thing that everyone needs to understand about Kooikers is that they are NOT small setters or retrievers, nor are they larger Cavaliers with better hearts! While they are indeed sporting dogs, in terms of their mentality and temperament they are as far from a lab or a golden as any terrier or guardian breed. Almost everyone comes to Kooikers from a different breed (often downsizing) but expecting them to behave and interact like any other breed, will not lead to a particular understanding of this one. So first, I encourage everyone to cultivate a deep understanding of how a Kooiker is SUPPOSED to behave.

According to the VHNK’s website, “the Kooikerhondje is originally a working dog: he is the assistant of his boss, guardian of house and property, and destroyer of mice and rats… he is always very watchful, but only comes into action when there is a good reason for it. He is quite sensitive for noise and screaming. He does not get along with everybody. In the beginning he can be a bit reserved towards strangers, children and other dogs. He will probably flee or growl when he feels insecure, depending on his spirit. But once he has accepted someone, it is the beginning of a lifelong friendship.” (

Kooikers are supposed to be alert and territorial. When not actively working their eendenkoois, they were expected to patrol the area and alert to any intruding humans, dogs or duck predators – and while doing that, they were meant to hunt rats and other vermin that presented a threat to nesting ducks and/or their owner’s food supply. This work requires loyalty, quick intelligence, independence, fearlessness, and a predatory instinct to rival a terrier’s. These traits you would more commonly see associated with working or guarding breeds, or again in a terrier. These are NOT traits found in most of the sporting breeds. So when discussing temperament or behavioral issues, the first thing to sort out is – is the Kooiker behaving as a Kooiker should, and it’s being misinterpreted by the owner?

Is the dog barking at the mailman when he comes on the property? Is he wary of strangers approaching you? Is he slow to accept new dogs in his circle? Does he chase neighborhood cats? I would argue that within reason, all of these situations are not problems but manifestations of a Kooiker being a Kooiker. Some of these would be inappropriate behaviors in other breeds, of course – but we must be wary of punishing or trying to “train out” behavior that was selected FOR amongst generations of their ancestors. These behaviors may be correct for the breed but incorrect for a specific owner, which is where the strife occurs.

True aggression is a different beast entirely and not one that should be tolerated. Unprovoked, vicious or repeated attacks on either a dog or a human by a Kooiker crosses a line into clearly undesirable behavior, and that is not what I mean by allowing for sharp behaviors by a Kooiker due to them being essential to their ancestral working conditions. Truly aggressive dogs need to first have underlying medical conditions ruled out or addressed, and then the advice of a good trainer or behaviorist should be sought. Aggression should be reported to the Register, and – as unpleasant as it is – I am not opposed to euthanasia for these irredeemably aggressive cases when quality of life for both dog and family and rehome-ability is jeopardized.

Socialization, Nature vs. Nurture (“It’s All In How You Raise Them”)

Are the many reports of poor Kooiker temperaments simply the result of undersocialization or failed training? Certainly that cannot be ruled out but in this century anyone touting the old “it’s all in how you raise them” phrase is dangerously behind the times. Recent research has narrowed down the heritability of many traits, including for phenotype (such as hip dysplasia) but also for behavioral traits. Epigenetic research has shown that specific phobias can even be transmitted from both parents to their offspring.

As an overgeneralization, temperament is about 50% inherited from parents. It’s important to control the other 50% by careful, positive socialization and training (both while the puppy is with the breeder, and after it goes home). Puppies should be exposed to new things, places, and people at least daily, continuing for much longer than would be required for an “easier” breed. Kooikers mentally mature quite slowly and I wouldn’t call a two-year-old “mature.” I slow down intense socialization protocols between ages two and three. One six-week puppy class is NOT sufficient to set up a Kooiker puppy to be well-socialized for life. Kooikers take a lot of work to “get right,” but all that hard work will pay off when you have a wonderful adult companion.

Once your puppy comes home, there is nothing you can do about the 50% of their personality that was inherited from their parents. So while looking for a puppy and a breeder, be very picky. Ask questions and be alert for red flags in the answers. There ARE, today, aggressive or otherwise subpar dogs being bred and sold to unsuspecting puppy buyers – do your research and avoid these. Can you speak with anyone else who has met the parent dogs (at a show or event or even their vet)? If not, why? (Do they never leave the house due to reactivity, or just because they live in the middle of nowhere?) Can you talk to owners of your potential puppy’s grandparents, aunts and uncles, or half-siblings? Do the parents have performance or show titles? If not, why not? This one is tricky because I don’t believe a dog has to be a show champion to be a good breeding dog (especially within a small population!). However, keep in mind that dogs are disqualified from show and performance events for bad behavior so a title means at minimum the dog made it through that event without biting someone, which is slightly more information than you’d have about that dog than if it had zero titles. Meet as many dogs as you can, talk to others experienced in the breed who have met the dogs as well, and be very alert for any red flags when speaking with breeders.

Keep in mind, especially in this country but internationally as well, Kooikers are big business. Those producing puppies for profit have no incentive to be truthful about their dogs or their temperaments – blaming poor temperament solely on other breeders or claiming to have “never had a problem.” Breeders presenting only a rose-tinted version of how a puppy will likely behave without acknowledging the real possibility of temperament issues cause damage to puppy buyers and the breed’s reputation. If a breeder is saying your puppy will behave like the mellowest Golden Retriever – run. Even if that’s what you WANT to hear about this breed – it is neither likely nor true, and I’d urge you to think carefully about your breed choices.

I feel some guilt about this, personally. My current dogs have wonderful temperaments, and we used to do a lot of Meet the Breeds events while working towards full AKC recognition. Guess what – my dogs’ parents also have wonderful temperaments and they came from excellent breeders, and were raised by me, someone already familiar with the breed and their socialization requirements. My dogs are examples of how great this breed CAN be, but for many people their reality is very different. I believe my dogs set an unreasonable breed expectation for those who met them as examples of Kooikers, and it’s thus my responsibility to speak openly about realistic temperaments in this breed. I did live with a reactive Kooiker for twelve years, so I do know what it is like, and also learned what to look for in future dogs, and if speaking openly about temperament problems means someone else doesn’t have to “learn the hard way” then it is worth posting about.


I have met through my website a surprising number of individuals looking for a sounding board on this topic. I find myself unable to respond to every inquiry asking for training/behavior advice, so here are the general resources I will reply with.

  • Your breeder – whether or not your breeder is a supportive resource, they need to be aware of your situation and your questions long before internet strangers are.
  • Behavioral resources – do some research to understand your dog’s behavior. Check out articles and books by authors like Dr. Sophia Yin (Cattle Dog Publishing), Ian Dunbar, Leslie Mcdevitt (Control Unleashed), and Grisha Stewart (I highly recommend her BAT 2.0 curriculum for both preventing and working on reactivity).
  • Find a good behaviorist/trainer. If you have tried one and it’s not working – try another one. I highly recommend with this breed to find someone well-versed in positive reinforcement training. A good place to start is the directories for Certified Animal Behaviorists, Fear Free Certified Professionals and the Association of Professional Dog Trainers.
  • Use your community. You may have a rare breed and feel alone, but there are a lot of us that are very active – if you know where to find us. Join the clubs, and join Facebook Kooiker groups – that is the best way to plug into the international Kooiker network. Ask for trainer/behaviorist recommendations directly from people who may be able to personally advise.
  • VHNK Behavior Counselors– our breed’s Dutch parent club, the VHNK, has volunteer behavior counselors listed at this link. They are experienced in the breed and available for consultation even from abroad.