COI Chronicles Part III

COI Alone is Not Enough

A 10-minute read about the role of COI in evaluating litters/dogs.

Although the Coefficient of Inbreeding (COI) is important, there’s much more to successful breeding programs…those that continue to produce excellent dogs year-after-year…than COI. 

From COI Chronicles Part I:  The 10% Rule Clarified. The 10% rule is a historical calculation of risk developed before genetic testing was available to breeders.  It’s a mathematical statistic that is routinely misapplied, and should never be used as a stand-alone measure of the quality of any given breed, litter nor dog.  The number of generations used in the calculation and unknown/missing dogs in a pedigree can both influence a COI calculation, typically lowering it and producing an understated level of risk.  If you’re not using a 10-Generation COI calculation the 10% rule isn’t applicable.

From COI Chronicles Part II:  How High is Too High? It’s virtually impossible to produce purebred dogs with a 10-Generation COI of <10% and/or a Genetic-COI <20%.  Each purebred breed has its own breed standard made up of specific physical and behavioral traits.  Each purebred breed also has its own unique average 10-Generation COI, making the “Keep it below 10% COI” guideline flawed when applied ad hoc across breeds.  What’s important is the variance between the average COI of a purebred breed in general, and any litter, dog or potential breeding of the same breed.        

Given those 2 clarifications, how then are COIs used in practice when evaluating a potential breeding or a single dog?    The goal of Castiron Kennels is to produce cooperative Picardy Spaniels that hunt like hell afield, but are also people-centric and have an off-switch in the house.  COI, while important, is only a single consideration of many.  Our evaluation process…the 4-F’s.…Fundamentals, Function, Form, and Forgiveness…help us rate litters, individual dogs and also potential breeding pairings.  Because there are so few Picardy Spaniels in North America, we are always looking for a litter/pup that will expand the gene pool, maintain the breed standard, and come close to our definition of “the perfect” Picardy Spaniel for North American hunters.  What follows is a summary of the process we went through when looking at a particular litter (Amber/Omer) whelped in Germany. 


Fortunately, research in this quantifiable category was easy to do from afar using breed club databases and by talking to European Picardy Spaniel breeders.

  • COI – Because genetic-COI testing is relatively new in this breed we needed to use an 8-Gen COI.  With virtual breeding software we determined the Amber/Omer litter had an 8-Gen COI of 9.7%.  For reference, all of our Picardy Spaniels 8-Gen COIs are between 7-10%.  We then used virtual breeding software to run scenarios with Manny, our foundation sire, our top A-litter and B-litter males, as well as a handful of other males in North America.  All of the scenarios looked promising in terms of keeping the COI of a future breeding “low” relative to the breed average.
  • HD – Omer has A hips…the European equivalent of OFA Excellent, and Amber has B-hips the European equivalent of OFA Good.  Both of Omer’s parents have A-hips, as do both of Amber’s parents.  Of the 24 dogs included in the 4th and 5th generations in the pedigree of the litter 11 had A-hips, 10-had B hips, 1 had C-hips and one Great Grandparent’s hips either weren’t tested or weren’t reported.  Given the lineage we felt there was a low genetic predisposition to HD in the litter. 
  • Genomics – because there are very few health issues in the Picardy Spaniel breed, the recessive traits we look for are more cosmetic in nature.  Due to historical outcrosses with setters a Picardy Spaniel coat color could be brown, yellow (eLocus gene) or piebald (r-Locus gene).  Even though there are no health issues tied to the recessive color variants, we’ve only added dogs to our kennel that are homozygous dominant (EE) for the eLocus gene.  Because Amber is a carrier (Ee) and the breeder understands the importance of this criteria, she tested every pup in the litter.  Several females were EE, so we had a few options.
  • Logistics – importing dogs from Europe isn’t easy, nor is it cheap.  But because we were looking to augment the Picardy Spaniel gene pool in North America we didn’t have much choice.  About the same time we were evaluating the German litter there was an “accidental” litter whelped in North America whose bloodlines were attractive.  Even though the costs/logistics associated with acquiring a female from that litter were significantly better than the German litter, we opted out.  The owner of the “accidental” litter didn’t hunt her Picardy’s.  Because the Picardy Spaniel is bred to be a hunting dog, acquiring a dog whose parents don’t hunt wasn’t an option for us.
  • Breeder Reputation/Experience – this was the first Picardy Spaniel litter for the breeder, but Laura came from a family who bred dogs.  She was also connected to and mentored by a very experienced breeder, Diana.  The Picardy community is quite small, and we had acquired Cleo, our foundation dam, from Diana.  She fielded questions from us about Laura, Amber and Omer, and also from Laura about us. A good breeder cares as much about producing good dogs as they do about placing them with good families…not just anyone who has cash-in-hand.
  • Prior Progeny – neither Omer nor Amber had any prior offspring, so that in itself was a bit of a concern.  It’s always nice to be able to scrutinize prior litters to see if they exhibit desired traits.
  • Sire/Dam Use – popular sire syndrome and/or dams that have multiple litters with the same sire is a common, yet challenging situation in most breeds.  On one hand you have a good idea of the quality of puppies that will be whelped.  On the other overuse is counterproductive in terms of expanding the genetic diversity within a breed.  We consider not only whether the sire and dam have been used excessively, but also how often the dogs in their respective lineages were bred.  In the German litter there were a couple “usual suspects” that showed up in their pedigrees, but they were 5+ generations back.


For the past 100+ years Picardy Spaniels have been bred to be versatile hunters as well as good family dogs.  Evaluating dogs that are overseas or even dogs that are hundreds of miles away can be challenging in that you need to use second-hand information when assessing them.  We rely on breeder input…verbal, video, pix, stats, etc…corroborated by any and all information we can find on social media.  The Picardy Spaniel is a hunting dog, and we evaluate hunting prowess by looking at:

  • Prey Drive
  • Water Affinity
  • Pointing Style
  • Search Style
  • Retrieving Afield
  • Cooperation Afield
  • Tracking Ability
  • Demeanor

Rating dogs in these functional areas is pretty subjective, and the best way to determine whether a puppy will exhibit these characteristics is to hunt behind, and/or spend time observing training of the sire and dam.  Testing is another way to assess these characteristics, but anyone who has ever tested a dog knows that test scores don’t always tell the whole story.  On “test day” a phenomenal dog can have an off day, and/or a mediocre dog can have its best day.  Unless you attended the test you have no idea as to whether weather conditions, judges experience with a breed, quality of birds in the test, etc. played a role in the outcome/test score.  Test scores are a bit like COI calculations in that the devil is in the details. 

Assessing dogs you’ve never seen in person boils down to secondary data and trust.  Both Omer and Amber hunt regularly, and both have passed several European hunting tests.  Our conversations with Laura and the pictures/videos of Amber and Omer we found on social media gave every indication that both parents are proficient hunters.  Further checking with other Europeans who had personal experience with both dogs corroborated everything we had seen and heard about their overall hunting prowess.


Form comes AFTER function when we evaluate a litter or an individual dog.  Maintaining a breed standard is important regardless of the breed, but we all know of breeds that’ve had “the brains” and “hunting instincts” bred out of them in favor of cosmetic attributes.  As Craig Koshyk so aptly put it: “Picardy Spaniels are bred for hunters by hunters.”  That said, Picardy Spaniels are truly beautiful to watch afield.  So, while form takes a bit of a backseat to function, it is still very important.  When evaluating a litter or individual dog in this category we assess the following characteristics:

  • Size
  • Structure
  • Gait
  • Coat Type
  • Teeth
  • Eyes

Rating dogs in these areas is much more objective than rating functional areas.  Size is easily quantified, for example, while measuring prey drive isn’t nearly as black-and-white.  Most of the ~280 Picardy Spaniels in North America today are on the top end of the breed standard for size.  So, we felt somewhat obligated to find a smaller female, even if we had to compromise a bit in other areas.  Coat type is not an area where we will compromise however.  Picardy Spaniels can have a smooth, flat coat, a thick wavy coat or a very curly coat.  The smooth, flat coat is our preference as it attracts fewer weed seeds/cockleburs and is easier to maintain.  Butt bite is relatively common in the breed, and although it’s not a breed fault we try to steer away from dogs with butt bite.  Dark brown eyes are preferred over yellow eyes in Europe of late, but eye color isn’t a trait we’re concerned with as there’s no genetic health issues tied to color.

As with Functional characteristics we needed to rely primarily on secondary sources for information as we evaluated Form for this litter.  Our European friends confirmed what we observed in pictures.  Omer is well-boned and on the higher end of the size standard.  Amber, on the other hand, is a bit smaller and of a slighter build.  Both hunt with continental style and both have smooth flat coats, albeit Omer’s is a bit thicker.  Omer and Amber both have proper scissors bites and neither has a butt bite.  Lastly, as far as we could ascertain, neither has any entropion in their lines.


With very few exceptions no single dog nor litter meets nor exceeds expectations in every category.  To maintain overall health within a breed the gene pool needs to stay as large as possible…once genes are lost from a gene pool they may be lost for good.  Practically speaking, Forgiveness is all about tradeoffs.  That’s why many people refer to breeding and/or selecting purebred dogs being “as much art as science.”  In our breed there are only about a dozen litters whelped globally in any given year, so timing can impact the “forgiveness factor” as well.  The ultimate question to be answered is: “How does a dog/litter stack up to expectations in all of the categories?” 

As self-proclaimed spreadsheet geeks we’d love to build an algorithm that would help us score quantitative and qualitative assessments, while at the same time balancing the impact of any tradeoffs.  To date we haven’t developed anything that works any better that a simple green-, yellow- or red-light rating.  Green being an obvious “proceed,” yellow being “proceed with caution” and red being “proceed at your own risk.”  Yellow lights are the easiest tradeoffs to assess and decide upon.  Red lights require a quite a bit more thought.  Our rating of this litter was as follows:

In this case the Omer/Amber litter had plenty of green lights, including COI.  And the single red light…total cost to purchase the puppy and to fly to Germany to get her…and the lone yellow light…first breeding for both the sire and dam…were both within our “acceptable risk” tolerance.  And, there were several solid females that were homozygous dominant (EE) for the eLocus gene.  Laura was kind enough to send pictures, videos and puppy updates regularly and we narrowed the field down to 2 females.  As it happened those 2 females, Whiskey and Ivy were high on the breeders list as well, and she planned to keep one of them.  We selected Whiskey.  And, although it happened a year after we decided to adopt Whiskey, her dam Amber won “Best of Opposite” at the International Breed Show in France.  That, combined with Whiskey’s hunting prowess during her first 2 seasons, confirmed we made a good decision to adopt a puppy from this litter.

Without breeders deliberately breeding to perpetuate breed standards there wouldn’t be purebred dogs.  It’s a balancing act though.  Producing purebred litters has inherent risk no matter the breed.  COI is an important risk management tool for breeders and puppy buyers alike to include in their evaluation of dogs and the risks inherent in any particular breeding.  Too high a COI significantly decreases genetic diversity and hybrid vigor.  Too low a COI decreases the likelihood of maintaining the breed standard.  But, there’s much more that should go into the evaluation process.  And when the cards are all on the table and the COI is “too low or too high,” a breeder has to make a judgement call as to whether the other criteria are strong enough to proceed with a breeding.  That’s why COI alone, even if it’s calculated correctly, or measured via genetic testing, should only be one of multiple measures in the evaluation process of any litter, dog or potential pairing.  Again, breeding is as much art as science.

Ric, Ellen and their 4 Picardy Spaniels live in New Glarus, WI just 25 minutes southwest of Madison.  A lifelong hunter, Ric has trained and hunted Small Munsterlanders, Gordon Setters, and for the past 6 years Picardy Spaniels.  Ellen has an extensive background in animal genetics and a PhD in Reproductive Physiology.  She bred and trained Greater Swiss Mountain Dogs prior to Picardy Spaniels.