An Acceptable Risk

Being a breeder in this age of scientific overload comes with more questions than science has answers.  Is it better to know of genetic conditions in your line, or breed in general, or proceed as if there were no tests available and make decisions based on pedigrees, personal tastes and magical thinking.  The Kerry Blue Terrier is a healthy breed.  It is also low in popularity and numbers.  The breed is not heavily puppy milled, or backyard bred and is for the most part, in the capable hands of caring hobby breeders.  There is a fairly diverse mix of older well established lines and breeders and people just starting out or in the breed less than ten years.  It is this later group that is the driving force behind the plethora of genetic tests available for the breed.  These are the people, it seems, that may right our course and preserve the health we value.

As dogs have moved out of the yard and into the livingroom, often replacing children in some people’s lives, the expectation of healthy, long-lived pets has increased.  Fifty, or even thirty years ago people didn’t expect their dogs to live past ten or certainly past thirteen years of age.  It was accepted that dogs died from injury, disease or developed debilitating health problems as they got older. Few questioned any of this including breeders.  People did the best they could with the stock they had. 

Fast forward to today.  Our pets are fur people.  We monitor our own health as never before, and have ourselves tested as much as our wallets and insurance can stand.  Similarly, expectations for the lives of pet dogs has changed.  Money spent on veterinary care for pets is up and people expect to get healthy puppies from breeders.  We spend a  lot of time smugly telling potential buyers how we test for this and that and some breeders offer health guarantees.  But now, we as breeders are privy to so much more genetic information about our breeding dogs, readily available if you care to pay for the testing.  In our breed you are expected to check the hips and eyes on the dogs you anticipate breeding.  These two tests are the minimum required for our breed by the Orthopedic Foundation for Animals to certify a Kerry Blue Terrier as a CHIC dog.  The board of our national club, and its Health and Genetics committee, debated about which tests to require.  It is interesting to note that the board members are primarily people who have been in the breed an average of twenty years. There is more than 200 combined years of experience in the breed at every meeting, but if you check the OFA database for tests done on Kerry Blues, you will not find dogs belonging to board members outside of the hips and CERF tests.  You will  not find a lot of Kerries in the database in general.  This makes informed choices about breeding difficult.

If you began breeding in the eras where testing was in its infancy, you judged the health of your line on what you saw.  How long puppies born in your home or kennel lived, what they died from, how long their puppies lived and any visible physical problems dogs you bred possessed.  There were rumors of sick litters (PNA) from some people, eye problems and hip issues were whispered about, but nothing concrete.  Few breeders would share information or admit anything negative.  Some did and were ostercised or run out of the breed.  Others kept quiet and endured the sadness and fear alone.  Nobody wants to see puppies with disease or genetic defects.  Nobody wants to sell them and no one wants to buy one.  Sadly, many in our breed have never moved past this.

Slowly, breeders of all breeds began demanding tests to aid them make better breeding choices.  In the last dozen years there has been an explosion of testing and an equal firestorm of hysteria.  There is a trend toward the disease du jour.  Pre-Mick it was the hips.  Dogs and bitches with an OFA hip rating of  “Fair” were somehow less worthy of being bred.  Even though the mode of transmission of dysplasia is not fully understood, and people forget that two “Fair” dogs can produce offspring with an “Excellent” rating, some breeders refused to breed to a “Fair” dog or purchase puppies from a “Fair” bitch.  Then the great Kerry Blue, Mick, was found to have “Fair” hips.  People put aside the hysteria and bred to him anyway.  Some breeders rarely tested hips before this time and some still don’t test today.  The reported rate of dysplasia is only 6% of the dogs tested.    

VonWillebrand’s and Factor XI, bleeding disorders, were the next hot button tests.  These were among the first rounds of genetic testing available for our breed.  Most people had never owned or known of a dog with either condition.  But somebody had, and there was a test, so dogs were hurried into the testing process.  Still, some breeders don’t test now for either one and the hysteria has died down.  If you do test, it seems safe to admit your dog is a carrier for these conditions now, but at first it wasn’t.  Many people won’t let their carrier dogs be used by others with dogs that aren’t clear.  This seems a reasonable approach as long as there is an acceptably deep pool of clear dogs and bitches.  There are some dogs found in the database for these two disorders, but not nearly enough to give breeding options to most breeders.  Supposition and word of mouth are the only guidelines available on a large-scale.

Now we have a new scourge.  It is Degenerative Myelopathy (DM).  It is a degenerative disease of the spine that renders the rear legs of a dog useless.  This is a double recessive gene and so it takes two carriers, or two dogs who themselves are at risk to develop the disease being bred, to produce puppies that may develop the condition.  In the case of two carriers being bred, there is a probability that 25% of  the puppies in a litter will being at risk. There is also the probability that 25% of the puppies will not carry the mutated genes at all.  50% of the puppies produced from two carriers will certainly be carriers themselves but will never develop the disorder.  So the question every breeder asks themselves is:  Is this one in four chance of producing an at risk puppy an acceptable risk?

In the case of DM, dogs testing at risk, those that have two copies of the mutated gene, may never develop any clinical symptoms of this neurological disorder in their lifetimes.  It is far more likely the dog will die of something else before the gene expresses itself.  DM is always late onset, usually after age 8, and most people in our breed cannot recall ever knowing of or seeing a dog with this illness.  Maybe this is why so many breeders don’t test their dogs.  The OFA says breeders whose dogs test as carriers or at risk, to consider these results as you would any other fault.  But a bad head or bad topline, won’t kill a dog or make the owners of a puppy you bred call you crying in ten years to tell you their dog can no longer use his back legs. 

You cannot hold a breeder responsible for what he or she doesn’t know about his breeding dogs.  But what about holding them responsible for not being willing to know?  And once you have tested your dogs and the results are not what you’d hoped or expected, how can you not hold yourself responsible for what you will produce and sell?  In the case of these genetic disorders a conscientious breeder would turn to a pool of clear dogs for incorporation into the line.  But these dogs are absent from our databases.  There are so few that using them is not a viable option.  So the question persists.  Is the risk acceptable?  If more breeders would test more dogs and allow the results published in an open database more choices would be available to everyone.  But in our breed, we are slow to embrace the new science.  We have under-reported the incidence of hip dysplasia and eye disease and many well-known and well-regarded breeders don’t do the testing.  What is the chance that we will seek testing for the more exotic diseases.

This antiquated attitude needs to change.  If a tree falls in the forest and nobody is there to hear it does it still make a sound?  The laws of physics say it does.  If you don’t test your dogs for heritable genetic disorders does it mean they don’t exist?  The laws of genetics say they do.  Maybe we should believe them.

2 thoughts on “An Acceptable Risk

  1. I say test and make responsible sound decisions. Enjoyed reading the post. Also liked the photo of Ringo!

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