Stud dog ownership: breeding, freezing, and infertility

Owning a male dog that may be used for breeding, whether you think of yourself as a breeder or not, requires a bit of familiarization with some potentially-awkward concepts and situations. As someone who studied reproduction well before I ever considered keeping an intact male, I wanted to share my experience to increase the transparency of the process and also to dispel awkwardness! 

Many Kooikers are kept intact for health and rare breed/genetic diversity reasons, whether or not they are ever bred. This decision is up to the breeder and owner, but at some point, some management will have to occur. There are 3 main experiences you will encounter if you keep an intact male dog in this breed: breeding, semen evaluation, and freezing. The fourth experience you may encounter is infertility, which is unfortunately common in Kooikers.

Semen Evaluations

Before breeding or freezing, it’s very likely a breeder will request a semen evaluation or analysis. These are usually done by veterinarians specializing in reproductive medicine (there is a search function on their Society of Theriogenology website) or potentially through an independent canine reproductive service, like ICSB. They will generally do breeding soundness examinations of the entire dog and evaluate characteristics of sperm quality and quantity like morphology, concentration and volume, and motility.

Collecting and Freezing

The science of canine reproduction is in its infancy and many findings and practices that are standard in humans and livestock are simply not possible in dogs. However, good quality sperm can be collected, cryopreserved, and stored for later use in breeding, which is advantageous for several reasons. First, if the male dog passes away, loses fertility over time, or is neutered, there is still a possibility of recovering his lines and producing a litter from his frozen semen. This is especially important in rare breeds whose individuals and thus possibilities for litters range widely both geographically and in time.  

To freeze semen, the owner will need to make an appointment with a repro vet or sperm bank such as ISCB (sometimes these banks are even mobile and attend dog shows). Sperm is collected, analyzed, and frozen as a test. Not all sperm survives the freezing process and it degrades over time even during cryopreservation, so top-quality sperm is required to freeze. Once a test freeze is completed satisfactorily, the sperm can be stored in pellets or straws nearly indefinitely. Annual storage fees are charged to the owner to maintain it in cold storage (and the owner of the sperm is always the owner of the stud dog at the time of collection, unless otherwise arranged). Fees are then also charged to use the semen in a breeding. International shipments of semen have to be frozen, and are shipped in liquid nitrogen transport containers.

Peak sperm quality and quantity in dogs will statistically occur when testosterone peaks during puberty, so a dog intended for freezing may benefit from a collection when he is 8-10 months old. This does seem absurdly early and is thus controversial since it is well before health testing, mental maturity, and “proving” the dog in the show ring or performance events. But science tells us that after the testosterone peak, sperm quality parameters will only decrease with age, so it is a consideration especially in this breed.


To get top quality sperm for freezing or breeding, there are a few general rules breeders follow – very few of which are backed up by any real scientific data.

  • Physical condition – the dog needs to be sparklingly healthy in order to produce healthy sperm. Maintaining proper weight, physical fitness, grooming, and treating any health problems are essential to producing quality sperm. Diet should be well-balanced and minimize ingredients containing phytoestrogens like soy and peas. Testicles are not necessary for survival, meaning evolutionarily they are the first organs impacted by sub-par conditions or stress – so stud dogs need to be kept as healthy as possible. 
  • “Clean out” collections – sperm quality has been shown to improve with regular ejaculations. Many breeders and repro vets will encourage doing at least one, but preferably a regular series, of collections well ahead of a breeding just to “clean out” any dead sperm and stimulate further spermatogenesis. This also prepares the dog behaviorally for collection for a breeding that is not done via live cover – this is an opportunity to put “donation” on a cue and approach it like any other behavioral training you might train your dog to do. Often the repro vet’s office is scary for a naïve male dog so any training and experience he has beforehand, the better the visit will go.
  • Fine-tuning? Sperm creation takes approximately 60 days, so any changes or improvements made with the aim of improving sperm quality can’t be really evaluated until 60-90 days after the change was made. This means the stud dog owner needs plenty of lead time if a problem is noted and a breeding or freezing plan is upcoming.
  • Testing – other than health testing, which any breeding dog should already have, consider Brucellosis testing, which is a blood draw sent to the vet to test for a contagious disease that can be transmitted via breeding (or just coming in contact with it in the environment). A breeder may insist on this, and certain countries may not accept shipped/frozen semen imports without accompanying proof of a negative Brucellosis test.
  • Extenders/cryoprotectants – different dogs’ semen reacts differently to the various chemical enhancers that are included in semen shipments or freezing units. It is a little out of reach of most male dog owners to test which ingredients or products work best for their dog, but if evaluating infertility, or if a specific product worked well previously, make sure to consider which product and ingredients are used.
  • Supplements – there are a few commercial supplements on the market that are noted to improve sperm quality. While some claims are dubious, most likely these supplements will either have no effect or very slightly improve quality. None will fix deep-rooted systemic problems. Supplement ingredients commonly floated in the dog fancy, some with more scientific support than others, are:
    • DHA (omega-3s)
    • Vitamin E and/or C
    • Selenium
    • Silica – DE
    • Linoleic, linolenic, oleic acid
    • Orthopedic products like Glycoflex (green lipped muscle)
    • Antioxidants
    • Carnitine


Unfortunately, many Kooikers experience subfertility or infertility. In other animals, fertility issues are associated with inbreeding, and while this may be the case in Kooikers as well, there is no clear correlation between measures of inbreeding like COI and infertility. Similarly, there do not appear to be certain less-fertile lines, but it does seem across the board that fertility decreases sharply with age.

We were devastated to have to work through this recently with our Huxley, who we concluded ultimately is infertile. From his very first collection at a year old (intended to prepare him to have a semen sample frozen) he had exclusively malformed sperm in low numbers. While we tried many interventions and consulted with multiple repro vets, his sperm never improved to a level anywhere near where it would need to be to produce a pregnancy. As a last resort we neutered him and sent his testicles for pathology in case there was anything to be learned that might impact his relatives or the breed as a whole – unfortunately, the pathology came back normal. From working through this terrible experience though, there are a few things I would recommend anyone to consider if they have a male dog that may be intended for breeding someday:

  • Collect and evaluate early. I’d recommend doing an initial evaluation around a year of age, and that becomes your “baseline.” If there are issues then, you have time to work on them before breedings take place – or if it looks irreparable already (azoospermia, for instance) you won’t waste time and money on preparing this potential breeding dog.
  • Subsequently, make a plan to re-evaluate every 60-90 days.
  • Evaluate everything going into the dog, and everything he encounters in life. What is he eating, what is he drinking? Does he have supplements, flea or heartworm medications interfering with his sperm production? Is he encountering pathogens he is mounting an immune response to, even without appearing ill? Is he stressed by a life circumstance like being campaigned in shows, or being around other dogs or humans that stress him out? Change or reduce one of these factors at a time, re-test, and see what worked.
  • If there is an issue, prepare to do diagnostics like blood, semen and urine cultures and analyses. Testicles are “immune-privileged” which essentially means that even if the dog is clinically healthy, something very wonky could be going on in the testicles and it would not necessarily be reflected in his general health or behavior.
  • Very often the cause is not identified. Infertility can be caused by such a wide variety of problems, from developmental abnormalities, to a missing nutrient in a diet, to infectious disease, or some issue within the dog’s genetics. It’s very likely that an “answer” to why a given dog is subfertile or sterile will never appear.

If you are a male dog owner and are struggling with anything discussed here – shoot me an email. Reproduction is a hard topic for some to discuss and that may lead to stud owners feeling unsupported. You are not alone!