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Nederlandse Kooikerhondje:

Common Behavior Issues, Considerations,
Recommended Breeders

by:  Eileen Koval, CDBC, CBCC-KA, CPDT-KA



Kooikerhondjes are rapidly gaining popularity in the United States although they are still a relatively unknown breed.  It is difficult not to be drawn in by their fluffy tails, light-footed movement and sweet expression.  My husband and I have been Kooikerhondje owners since getting our first one in 2010.  She was an absolute dream so we eventually got two more!  We got our first one from an accidental litter, our 2nd one from an American breeder, and our 3rd one from an incredible breeder in France.  We have learned a lot about the breed since acquiring our first Kooiker, variations in behavior across the breed, and differences in the breeding programs and behavior of Kooikerhondjes here in the United States versus breeding programs in individual countries overseas. 

As a certified dog behavior consultant, I work every day with dogs who have severe behavior issues, ranging from fear and anxiety, compulsive disorders, and severe aggression.  I have also worked with numerous American and Canadian Kooikers with all of these issues.  While these behaviors can have environmental and social components, they frequently also have a strong genetic basis as we see them run in particular blood lines.  This is especially true for Kooikerhondjes.  Kooikerhondjes were originally bred to lure ducks into traps in the eendenkooi.  However, people often forget that they were also selectively bred over countless generations to be an all-around farm dog whose job was also to be on watch and alert to poachers on the property.  They were selected for alert, guarding type behavior with a natural suspicion of strange people and dogs.  The behavior issues I tend to see in Kooikerhondjes are similar to those I see in guarding breeds.  Most of us do not want a working dog, or at least not a watchdog or guard dog.  We are looking for a nice companion dog who can be handled, who can go into public places where other people, dogs, and children are present, to attend group classes with other dogs and owners, and to have family and friends over to the home without incident.  These are serious challenges for some Kooikers, particularly in the United States.  Socialization is also essential, but this is where genetics can have an immensely strong role in the personality of your Kooikerhondje. 

Many breeders in the United States identify as preservationist breeders and are looking to increase the numbers of Kooikerhondjes while maintaining genetic diversity.  Genetic diversity is lost every year when there is a closed gene pool and not all dogs are bred for various reasons.  They are also breeding to the AKC standard (adopted from the Dutch club) that focuses on appearance and proportions, so temperament may be a lower level consideration.  There tend to be more males born than females in Kooiker litters, so breeders may choose to breed females even if they have a questionable health or temperament.  That said, I have also seen some males bred who had poor temperament.  This all comes down to the choices of the individual breeder.  The excuse that is often used is that they were not socialized enough, but that may or may not be true.  If the parents are not a dog that someone else would want in their home then they likely are not going to produce puppies that prospective puppy owners would want in their home.  That is true for any breed or mix.


Our first Kooiker is highly sociable and absolutely lovely in every way.  Although we titled her in different sports and venues, it was difficult competing her due to her pervasive noise phobias and sensitivities.  We had to avoid indoor venues and covered horse arenas for both classes and competitions where noises are louder.  She cannot handle different environments and the noises they present and will try to flee as if her life depended on it.  Training helped it be somewhat more manageable to a degree, but she is still stressed in these situations and it is always there.  Not everything is a training issue.  Despite intense and sustained early socialization in a variety of environments these noise issues appeared around 6 months old.  


Breeders have differing opinions on who to exclude from their breeding programs.  Some exclude dogs with health or temperament faults like hip issues, fear, or reactivity, while others do not.  I recently had a conversation with a breeder who said that she was fine with breeding reactive or aggressive females because likely not all the puppies would be aggressive.  She said that if some of such a litter turned out with acceptable temperaments, wouldn't that be progress?  I was blown away.  How would someone feel paying $3000+ dollars (plus thousands on training and veterinary behaviorist's fees) to live with an aggressive dog for the next 12-15 years?  I had a separate conversation with another breeder about using dogs with hip dysplasia for breeding.  She thought that this was not an issue since not all of the puppies would have hip dysplasia, and that they could utilize the "good" genes from these dogs.  But what about the dogs who get dysplasia and have a life of pain and suffering?  There is health testing to reduce and nearly eliminate the risk of these inherited conditions.  Unfortunately, some breeders choose to ignore these health test results and look at breeding puppies as a long game of numbers, not looking at the individual lives they are producing and the health and quality of those lives.  Luckily, there are some breeders who find this risk unacceptable and do not breed sick, structurally unsound, or poor temperamented dogs.


Unfortunately, I know too well how this goes because that is what happened with my 2nd Kooikerhondje who was born with inherited health conditions after I was told the parents were fully health tested (they weren't...they were partially tested) and previous litters had displayed aggressive behavior and medical issues, unbeknownst to me until later. (Update: Beowulf passed away in Jan 2022 at 4 years old due to his inherited health conditions.).  We did much behavioral work with him so he made huge improvements, but our days revolved around his extensive health and behavior issues.  When we brought him home at 4 months of age, he was growling, lunging, and attempting to bite random people walking by, children and unfamiliar dogs.  I know of one of his siblings who was euthanized for aggression (I heard anecdotally that others also were), another who was returned to the breeder for aggression, and there were numerous other reports of aggression from the four litters that his parents produced together.  One of his nieces and another relative was diagnosed with the same pituitary issue that he had at a similar abnormally young age.  At least three breeders whom I am aware of are breeding his siblings despite all the aggression and health issues that existed amongst the siblings. 

My oldest and youngest Kooiker are truly easy dogs to live with and to train, so it is hard for me to come to grips with the behavior issues that I see and hear about when working with other Kooiker owners and their dogs, except that I saw the stark behavioral differences with my 2nd Kooiker.  When there are serious issues, which behavior issues do I see most in the breed in the US? (again, Kooikers who are both well-bred AND well-trained are less likely to have these issues and less likely in any severity): Owner-directed aggression, food aggression with people/dogs/other animals in the home, stranger aggression both in public and at home, dog aggression (can range from mild leash reactive to aggression toward any/all dogs), owner guarding from other dogs/spouse/family members/other people, location/territorial guarding, sleep aggression (upon being awakened), fear of or intolerance of body handling, redirected aggression onto the owner or other family dogs, compulsive behaviors, noise sensitivities and phobias.  These are all behaviors that frequently stem from anxiety and from selection of a dog who was originally bred to do a particular job that required watchful, independent behavior.  

I chose to obtain my newest Kooikerhondje from an excellent breeder in France because the French version of AKC (Société Centrale Canine) requires independent sociability tests for all male and female purebred dogs when they are adults before they are allowed to be confirmed in the breed.  That means that they cannot have puppies that are papered unless they have a sociable temperament, which is what most people want in a dog anyway.  Sociability has equal weight to the other defining characteristics of the breed in their system.  It may surprise people that it is not much more in cost to import a dog, including the travel costs to fly overseas to pick up your puppy.  Our male Kooiker from France is now 3 years old and has not disappointed one bit!  He is so much like my first Kooikerhondje but he does not share her noise sensitivities.  He is dashing, fast, fun, an incredible agility partner, and so incredibly sweet.  He is truly a dream come true.    


Our Kooiker from the American breeder had health and behavior issues that consumed our days, as much as we loved him more than anything.  He was eventually able to do some group classes -- after years of work -- but they were still very challenging for him.  We could not compete in dog sports, group classes were very difficult for him, and even having people over to the home had to be carefully orchestrated although he did eventually enjoy making some human friends.  He worked so hard and came so far but he was limited by his genetic health issues that affected his behavior.  This was after 3 years of behavior modification (I am one of less than 300 certified dog behavior consultants worldwide with the International Association of Animal Behavior Consultants) and the help of a veterinary behaviorist (there are less than 100 worldwide).  Getting access to these resources is not easy or cheap for the average owner.  Plus, the whole experience can be gut-wrenching.  We love all three of them, but think carefully about what risk you are willing to accept when you find your next puppy. 


  • Ask the breeder which male and female dogs she has passed over for breeding over the past five years (and how many) due to fear, anxiety, or aggression issues.  If they have not removed any then there is a problem.  No one breeds only perfect dogs.

  • Ask if the parents attend group training classes in close proximity with other dogs and strangers. 

  • Ask if the sire/dam show any of the behavior issues above, any reservedness, shyness, etc.  If they say that all their dogs are friendly with everyone all the time in all situations then they are likely not being entirely honest. 

  • Ask if any offspring from those individual parents or the grandparents have had health or behavior issues

  • Meet the sire and dam, if possible, both in public places as well as in the breeder's home.  Their behavior is a good predictor of the puppy you yourself would take home.  If you cannot meet them, ask for videos of the dogs in a group class or in public.  Take note of whether the dog in question is on a loose leash when in public with a flat collar or harness.  I have seen plenty of highly reactive dogs appear non-reactive when on very tight control with a show lead, choke/slip lead, or prong collar.  

  • Check the OFA website and ensure that ALL the recommended tests have been completed with normal results for your breed of dog.  OFA has changed their reporting rules so that test results that fall outside normal limits (like a dog who has hip dysplasia) do not show on the results page.  If it does not show, do not assume that the dog has satisfactory results.    

  • Do not trust anyone who says the dogs are "fully health tested" unless you have seen the results of the tests and that all tests are complete (see above about OFA)

I hope that this has been helpful so you can better navigate the world of Kooikerhondjes, although the things I mentioned above are things that anyone should ask a breeder before getting a puppy.  If you have questions about Kooikerhondjes or would like help deciding which breed or puppy is best for you and your goals, please book a Virtual Consultation and I can assist you.  A companion for the next 15 years is a huge decision and worth the time, investment, and careful consideration.  

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Bones (11), Beowulf (3), Gilgamesh (2)

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