Tag Archives: genetic disorder

Death by a Thousand Health Tests

Food for thought is always a good thing, at least in my world, it keeps my mind open to new ideas. As I’ve aged I’ve found it’s ever more important not to get stuck in my ways and thinking about what other people have to say on a topic keeps me out of ruts.  So when I read the article I’m sharing with you today about health testing, I found myself thinking. Now, a word of warning, some of my close friends would tell you, “Sally’s thinking takes some rather weird detours now and again, so when she says “I was thinking” you might wanna run for cover!”

We all talk about being a responsible breeder, and of course, we consider a part of that responsibility to be health testing of the parents. Now mind you, I’m getting to that place where I’m almost old as dirt, so I’m one of those breeders who started in the game long before the majority of the health tests of today were available. While I’m all for health testing to gain knowledge of what is in the genes I’m about to mix together, I’m also one of those breeders who will tell you to use a good ole dose of common sense when breeding. While I’d never throw health testing to the side, I am also realizing that as the population of Gordon Setters declines, so follows our number of breeding options. This is a big conundrum we face folks, and it will take dedication, smart decisions and some good old common sense to preserve the best of our breed.

Sally Gift, AZ              Photograph by Susan Roy Nelson, WY

With that said, I don’t know as I agree with everything in this article, but I do know it will give you some food for thought so I’m sharing, for your reading and thinking pleasure.  If you’d like to share your thoughts after reading this feel free to use the comment section!

Breeder On The Edge

Death From a Thousand Health Tests by Amanda Kelly

AUTHOR:  A dedicated hobby breeder in a terminally rare breed, Amanda Kelly perpetually finds herself on the edge of everything from ecstasy to bankruptcy, quitting and insanity.

I had a really interesting conversation with a geneticist the other day that got me thinking: science is offering us more and more great ways to evaluate the health of our dogs…but when does enough turn into too much? When do we cross the threshold from helpful information to complete paralysis? Or outright bankruptcy? How do we avoid both?

Prioritization
The test we were discussing is quite a new one in my breed (Toy Manchester Terriers). It is for a condition called Xanthinuria that causes dogs to form a very rare form of kidney stone. There have only been three clinically affected dogs that I am aware of (full disclosure: we bred one). After encountering the issue, a fellow breeder did a little digging and discovered that a marker associated with the condition in humans worked for our breed as well. Kudos to her for being proactive and finding out more! The American and Canadian breed clubs helped proof the test and voila, it is now available commercially at quite a reasonable cost.

When I looked at dogs in my own breeding program that came up as carriers however, I was surprised as I would have expected more of our puppies to have or be forming stones than was the case.  So, what does that say about the disease? Do all affected puppies form stones? If not, what is the rate?  I found the answers to those Qs simultaneously helpful and troubling.

Apparently, current thinking is that approximately 50% of males with two copies of the mutation form stones or have associated kidney issues, while very few females with the same status have a problem (likely because they do a better job of emptying their bladders). Now, these are just rough estimates because the disease as a whole is rare and hasn’t been extensively studied, but it does raise an important question: what are we as breeders to do with this information and associated results of the genetic test?

The Jigsaw
The simple fact is that the more tests we have, the more pieces of info we have to try and reconcile when planning a breeding. At present, Toy Manchester breeders as a group are variously clearing things like hips, patellas, eyes, thyroid, and hearts plus DNA testing for von Willebrand’s Disease, and, now, potentially xanthinuria. That’s 7 tests, some with questionable value based on anecdotal and surveillance evidence, if we’re being honest. We’re also actively working to identify a test for juvenile cardiomyopathy.

The end result of all of that testing is a ton of information, which is great from the perspective of evaluating the health of individual dogs but also creates a number of very real problems for breeders in areas like liability, reputation and cost.

In the past, these factors were certainly in play but their effects were somewhat muted. Breeders worked for years to learn about their breed and their lines so they could make informed decisions and minimize the risk of producing issues. Health tests initially concentrated on measuring phenotype as an indicator and we worked with what we had. The important thing was that we could confidently tell puppy buyers we had done everything possible to produce healthy, happy puppies and if a problem appeared we were solid in the knowledge we had used all available tools to their best advantage.

Enter the genetic test. In my breed, the first one was for von Willebrand’s Disease (a blood clotting disorder). For years this disease was monitored by assay testing that measured the actual amount of the specific type of clotting factor in the blood and projected genetic status based on corresponding ranges. It was a pain to do but everyone muddled through as it was one of the few standard health tests most breeders did in the 1980s and 90s. When the genetic marker was identified, some breeders lost their ever loving minds. Dozens of valuable dogs were promptly spayed and neutered while breeders across North America began making pronunciations about “never” breeding a carrier even to a clear.

There’s no question, needless damage was done to the gene pool — especially when you consider there had never been a documented case of a Manchester actually bleeding out because it was vWD affected (at least not one I am aware of). Eventually breeders learned how to work with the DNA results and things calmed down. Our new test allowed us to easily avoid producing “affected” puppies (i.e., a dog with two copies of the gene, not necessarily clinically affected) and, regardless of the actual effects of the condition itself, doing so quickly became “right” and “just”.  It was an approach we ourselves endorsed and followed because, after all, “responsible breeders” test.

And thus, the line in the sand was drawn. It’s a line we in the dog community drew ourselves and it’s one most of us dare not cross.

Unlimited Liability
The scientific advancements that brought us more genetic tests took place against an active backdrop that included the rise of animal rights, increasing anthropomorphization of pets, emergence of puppy lemon laws, and the advent of social media. Now, it may seem odd to bring those factors into a discussion of genetic testing, but they each play a very important role in describing the environment within which we are working. An environment that values reputation above all else and that pits breeding decisions against financial liability in a way many breeders don’t consider.

Any breeder with two licks of sense knows that when it comes to breeding dogs, the most important possession you have — more important than any ribbon you may ever win — is your reputation. Your reputation affects everything you do, from access to stud dogs and puppies to demand for same. In a subjective sport like ours, it can even affect your ability to succeed in the show ring.

Protecting, fostering and growing a reputation can become all-consuming. Let’s cut to the chase here: We’re operating in an environment that can make a competition out of anything — which is why sometimes reputation management, and by extension health testing, becomes as much about one upmanship and moral superiority as it is the well-being of the dogs in question. That probably explains why many of the tests done in my breed are done by rote…because they are available, not because we have objectively identified a need for them. Not because we have established that rates of thyroid problems or eye issues, for example, are any higher in our breed than in the general dog population. No, we do them because we can and because we feel (tell one another?) that we should. And why is that? It’s because we have established as fact within our community that good breeders test and bad breeders don’t. So, we all work extra hard to make sure our conduct is above reproach.

That core belief is just as strong outside of the dog community, where we have worked hard to battle animal rights messaging by establishing health testing as a key feature differentiating responsible breeders from backyard breeders. And it’s a great message — easy to understand and easy for the public to actively measure when they are talking to breeders. The trouble is, that message comes pre-loaded with expectations we can never live up to. Expectations that if you buy from a good breeder your dog will never ever have health issues. That health tested parents won’t produce problems. That responsible breeders can be God.

And therein lies the problem. The more health testing we do, the bigger the gap grows between public expectations and the reality of what we can deliver…and with it, our financial liability. Because hey, don’t forget, in addition to health testing, responsible breeders also guarantee their puppies. Whether through provision of a replacement puppy or return of purchase funds, those guarantees do carry financial risk and can’t be dismissed at the best of times and even less so as puppy lemon laws increasingly make puppy health a legal matter. So, tell me…how do you think small claims court would view a breeder that knowingly produces a problem? Or one that unknowingly produces one because they failed to use the tests available? It’s a perfect catch 22 in the making.

Risk Reduction
It’s a simple axiom that the more health testing available, the less we talk about what we’re trying to avoid producing and the more we talk about what we are willing to risk producing. There isn’t a perfect dog out there and every biological organism possesses deleterious genes for something, regardless of whether we can test for it or not.  The more tests available, the more complicated planning breedings becomes because we all naturally want to avoid the chances of producing any problem at all.  But is that a realistic goal?

What did I say we were up to in my breed – seven tests? Eight? Heck, even I lose track sometimes. And all of these tests in an era when the number of puppies being produced continues to drop at an alarming rate. Under 200 Toy and Standard Manchester Terriers “combined” were produced in North America last year, so I’m sure you can image how difficult it might be to match test results for potential breedings (particularly if we’re testing for everything under the sun). Or what the costs of doing those breedings might be as we look further and further afield, let alone the relative cost of doing the health screening to begin with in a breed with relatively small litter sizes and low purchase prices. The financials would rock your world and have you questioning my sanity, so we won’t go there other than to say red is a better quality in a new coat than a ledger (but I digress…).

I asked a few researchers and vets what they felt breeders should do with test results when there are many to consider.  The consistent response was that we need to prioritize — and that’s a completely reasonable thing for a scientist to say…and a very difficult thing for a devoted dog breeder to actually do.

Never mind the costs, appearance or liability — I genuinely don’t want to be responsible through conscious decision for producing a sick puppy. It is one thing to employ testing, tools and techniques to theoretically reduce disease and quite another to look at a plethora of results and say “This one I can live with.”

And what happens once the die is cast?  If we use Xanthinuria as an example, I could choose to breed two carriers together and test all of the puppies…but then what? Sure, knowing a puppy has two copies of the gene and is at higher risk of forming stones will be helpful to an owner who could keep the dog on a low purine diet and perhaps avoid issues altogether…but could I sell a puppy like that? For how much? Would anyone take it if I was giving it away? What level of financial responsibility do I hold if it does develop an issue two, five or 10 years down the road? What if there are multiple puppies with two copies of the gene in the litter?

And that, ladies and gentlemen, is the ethical dilemma of the future.  Perhaps we in smaller, rarer breeds are dealing with it sooner, but it is a dilemma I truly believe every breed and breeder will face at some point.  It has the potential to be absolutely paralyzing as we seek to do the right thing in a world where that is increasingly less black and white than it seemed a few short years ago.

I don’t know exactly how we can or should approach it — perhaps I’m hoping you’ll be able to tell me. I suspect that monitoring of actual breed health through health surveys and breeders sharing information on what they are seeing will be increasingly important if we wish to prioritize according to real information. And I do know that one of the things we absolutely must do is change how we discuss health testing. The way we talk about each other (oh Lordy, put a star next to that one!) and to each other as well as how we portray ourselves to the public. Just as important, we have to think about health tests and results holistically in the context of our breed and gene pool. In our rush to erase problems through testing, we are shown again and again that the devil we don’t know is often worse than the devil we can test for.

What To Do?
This article isn’t intended to form the cornerstone of a campaign against health testing. Far from it. I truly believe we need to use the tools available to us, particularly if they are able to help us avoid devastating issues facing our dogs and puppies. In fact, I and others in my breed have worked hard for more than a decade to see a genetic test developed for juvenile cardiomyopathy because it is a brutal, deadly disease and I want all of us to have a tool that will allow us to make informed choices and stop guessing at how to avoid it.

But I’m also a realist. Health management is a tough nut to crack even for trained geneticists let alone the average breeder doing their best to navigate an increasingly complex and technical landscape. Giving us the test results is the easy part, it seems — figuring out what to do with them is our next great challenge.

Cerebellar Degeneration in the Gordon Setter

Thank you to Jerold Bell DVM for allowing us to reprint this article.

Jerold S Bell DVM, Tufts Cummings School of Veterinary Medicine, N. Grafton, MA USA

puppy by Silvia Timmerman
Photo by Silvia Timmermann

Cerebellar Degeneration CD (also referred to as Cerebellar Cortical Abiotrophy CCA, or Cerebellar Ataxia CA) is a hereditary neurological disease seen in the Gordon Setter breed, and caused by a simple autosomal recessive gene. It causes slowly progressive muscular in-coordination, with an onset or age of recognition of clinical signs between six months to four years of age. Pathology studies performed in the 1970’s show the onset closer to six months of age; but with mild clinical signs affected dogs may not be identified until later in life. CD is not related to the metabolic disorder lethal neonatal encephalopathy (DUNG’d) seen in 3 to 8 week old Gordon Setters.

The clinical signs of CD include: poor balance, frequent stumbling, a wide-based stance (feet planted far apart), a high-stepping gait, and head or body tremors. Affected dogs have normal mental alertness. Most affected dogs have a normal life expectancy, and pass away due to unrelated causes. There is no treatment for CD.

Drs. Alexander de Lahunta, Linda Cork, and Steven Steinberg published the clinical description and mode of inheritance of CD in the breed in the early 1908’s. In 2012, Dr. Natasha Olby at North Carolina State University identified the mutated gene. With autosomal recessive inheritance, both parent must be carriers of this mutated gene to produce affected offspring. Approximately one-quarter of offspring from such matings are expected to be affected; but statistical chance can cause none to several affected dogs in a litter. A genetic test is available for this mutated gene that will determine normal, carrier, or affected status. The test can be run at any age with cheek swabs, and costs $15 (US) per dog tested. (Submit DNA for Testing – NC State Veterinary Hospital).     (Link to form for submitting DNA for testing)

Gordon Setters affected with CD have been identified since a least the 1960s in both conformation and field trial lines throughout the United States, Canada, Europe, and Australia. Affected and carrier Gordon Setters worldwide do not “connect up” before generationally early ancestors of the breed. All confirmed affected Gordon Setters around the world have the identified mutated gene causing CD. This same mutation was identified in Dr. Olby’s laboratory to be the cause of CD in the Old English Sheepdog breed – showing a common ancestor as the original source of the mutation in both breeds. No other breeds have been identified with the same mutation to date.

Over the years, Gordon Setter breeders and owners have been surprised by a diagnosis of CD in their dogs, due to a lack of known relatives with the disorder. These occurrences are traditionally followed by more affected dogs from related lines. The ancestrally ancient origin of the mutated gene explains this occurrence. The mutated gene has been dispersed and propagated in the Gordon Setter breed since its origination. Now that there is an inexpensive and accurate genetic test for the mutated gene, ALL breedable Gordon Setters should be tested.

As with all testable simple autosomal recessive genes, quality carrier dogs can be bred to quality normal-testing mates. This prevents affected dogs from being produced. Quality normal-testing offspring should replace the carrier parent for breeding. Carrier offspring should be selected against for breeding homes. In this way, you have eliminated the single mutated gene, without losing the quality traits of the line. A genetic test for a simple recessive disorder should not change who gets bred, only who they get  bred to.

To assist breeders with health-conscious breeding, each dog’s results should be entered into the OFA Cerebellar Degeneration registry (OFA Form for submission of DNA). The test results will be listed on the dog’s OFA page. The cost is $15 per dog, $30 litter of 3 or more, and a kennel rate of $7.50 per dog if 5 or more dogs are entered by the same owner (all in $US). If a dog is out of two DNA tested clear Gordon Setter Parents, the OFA will provide a Clear by Parentage (CBP) certification. In this way, generations of Gordon Setters do not have to be tested.  CBP certification requires that both parents are CD tested and entered into the OFA registry, and that the parents and offspring have been DNA parentage certified (usually available through your national Kennel Club).

Cerebellar degeneration is not the most frequent genetic disorder affecting the breed, but is the oldest documented simple inherited disorder in Gordon Setters. With the availability of an accurate and inexpensive genetic test, no Gordon Setter, their owners or breeders should have to deal with the affected state of this disorder going forward.

(This article can be reprinted with permission from the author Jerold.bell@tufts.edu)

To order cheek swab kits by phone, call:
North Carolina State University Veterinary Genetics Laboratory
Phone-Voice Mail: 919.513.3314
Hours: Monday-Friday, 9 a.m. – 4 p.m.
Facility: NC State CVM Research Building

To order cheek swab kits via an e-mail at the following address:
vcgl@lists.ncsu.edu
Please state the following in your e-mail:
Your mailing address.
Number of kits you would like.
Type of test, (which breed), you are requesting,Gordon Setter, Cerebellar Degeneration.

Additional Links:  GSCA Health Survey 2004

(This article contains photos that are not intended nor do they relate to the content of the article.)

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