Purebred Dogs – Health Problems Due to No Health Testing

The first two reasons purebred dogs have so many health problems are...

1. Too much inbreeding
2. Some breeds are deformed

The third  reason purebred dogs have so many health problems is...

3. Not enough health testing

To avoid doing the three things above, what should breeders be doing instead?

I think we all would agree that every puppy brought into this world deserves the best chance at being born healthy.

That means breeders should be doing everything they can to produce healthy puppies. And THAT means:

1. Breeding dogs who are as unrelated as possible so that the risk of defective genes matching up is minimized, the risk of inbreeding depression is minimized, and genetic diversity is increased.
2. Breeding normal-looking dogs with sound structure. No deformities or exaggerations that increase the risk of health problems.
3. Testing every prospective parent dog for health problems BEFORE breeding.

Which health problems should a dog be tested for?

That depends on his breed. Some health problems are far more common in some breeds than in others.

Each breed has specific health problems to be concerned about. You need to know what those health problems ARE in the breeds you're considering. Why?

• Because you might decide that those health problems sound bad enough to make you eliminate the breed from further consideration.
• Because you need to find out if there are any pre-breeding health tests available for those problems, which if done on the parents before they were bred, improve your chances of getting a healthy puppy.

To research health problems, start with the Breed Reviews on my website.

1. From each breed's Review page, visit its Health page next; there you'll find the health problems that are most problematic in that breed.
2. Then visit that breed's Buying page; there you'll find my recommendations for the health certifications breeders should be doing for that breed.

The most common health tests

• X-rays of the hips, looking for hip dysplasia  which is a malformation of the hip joint that causes lameness and leads to painful arthritis. Hip X-rays are submitted to a health registry (OFA, PennHip, OVC), which issues an official hip rating such as Excellent, Good, or Fair. In the United States, OFA is the most commonly-used registry, though PennHip is more accurate. OVC is the Canadian registry.

  48% of Saint Bernards whose hip X-rays were evaluated by the OFA were dysplastic. 35% of American Bulldogs. 22% of Pit Bulls. 21% of Rottweilers. 20% of Golden Retrievers. 20% of German Shepherds. And those were just the X-rays that were actually submitted for evaluation.  Most owners don't even bother submitting X-rays that even they can tell won't pass!

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• Elbow X-rays look for... surprise! elbow dysplasia.  Normal  elbows aren't given a specific rating, like hips are. Normal elbows are simply rated NORMAL and the OFA issues a clearance certificate. If the elbows are Abnormal,  the OFA grades them from a less- awful grade I to a really awful grade III.

  51% of Chows whose elbow X-rays were evaluated by the OFA were evaluated as dysplastic. 39% of Rottweilers. 19% of German Shepherds. 16% of English Springer Spaniels. 12% of Golden Retrievers.

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• Physical palpation of the knees, looking for luxating patella,  where the kneecap (patella) doesn't fit tightly enough in its socket, so it luxates  (pops out of place) from time to time, causing lameness. For this exam, neither X-rays nor sedation are needed. The vet simply feels around the knee joints, then writes a report. Unfortunately, some vets are not skilled in evaluating the knee joint, plus the dog's anxiety and tension can affect the results, so these exams are somewhat suspect. And since the OFA simply accepts the reports at face value, an official clearance certificate for patellas isn't as useful as the previously-mentioned hip and elbow certificates.

  Toy breeds are especially prone to having Abnormal  patellas. Especially Pomeranians at 30% and Yorkies at 18%.

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• Eye exam by a board-certified canine ophthalmologist, looking for eye diseases  such as progressive retinal atrophy (PRA), which leads to blindness. If the owner submits the vet's report to OFA's CAER (Companion Animal Eye Registry), the OFA will issue an official certificate to dogs who pass. Eye examinations must be repeated every year. So a CAER certificate is only good for one year.

  Rough and Smooth Collies (77% Abnormal), Shar-peis (43%), and Chows (24%) lead the list of Abnormal eye results.

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• Cardiac exam by a cardiac specialist, looking for heart diseases. I don't mean simple "old age related" heart disease, but serious inherited heart defects  that can cut a dog's lifespan drastically short. In the most vulnerable breeds, before you breed them, a cardiac specialist (not a regular vet) should perform a thorough exam, which may include a Doppler ultrasound (echocardiogram) or EKG. The cardiologist's report can then be registered in the OFA's Basic or Advanced Cardiac Database.

  Bull Terriers lead the list of Abnormal cardiac results, with 22% affected. Shelties are at 15% and Cavaliers at 13%. Inherited heart diseases are also a concern in Golden and Labrador Retrievers, Boxers, Newfoundlands, sighthounds, and other breeds.

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• Blood test looking for hypothyroidism  (low thyroid). When the thyroid gland doesn't produce enough hormones to maintain a dog's metabolism, you'll see weight gain, lethargy, warmth-seeking behavior, and hair loss or dry brittle hair.

  The blood test must include ALL the thyroid hormones (not just T4), plus thyroid antibodies. If the serum sample is sent to an OFA approved laboratory and thyroid function is Normal,  the OFA will issue a clearance certificate. Michigan State University also maintains a large thyroid registry.

  The most commonly affected breeds include English Setters (up to 40% affected), Dalmatians and Boxers (26%), Irish Setters (20%), sighthounds, and others.

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• Any DNA tests  available for your breed, looking for a specific disease. DNA tests require only a swab of saliva from a dog's cheek or a small blood sample, which is sent to a lab that examines the DNA. Here are just two examples of DNA tests that are available:
  • DNA test for a specific form of the blindness-causing eye disease PRA in several breeds, including Labs, Cockers, Poodles, Australian Cattle Dogs, French Bulldogs, and others
  • DNA test for a neurological disease (degenerative myelopathy, similar to ALS in humans) in German Shepherds, Boxers, Welsh Corgis, and others

    DNA tests reveal not only whether a dog has or doesn't have the disease, but also whether he carries a gene for it that could be passed along to his offspring. Being a carrier  is harmless if the dog is not going to be bred, but essential to know if the dog IS going to be bred.

These tests aren't perfect!

Except for the DNA tests (which are very accurate), the other health tests we talked about aren't perfect.

Some dogs may pass a test simply because the health problem isn't yet advanced enough to be detected by the test.

The tests aren't foolproof, either. X-rays can be taken too young, or with the dog in a faulty position. Blood test results can be influenced by medications the dog is taking, by a female dog's estrus cycle, even by the stress of being in the vet's office.

The interpretation of these tests can also be flawed. One vet may declare that an X-ray shows hip dysplasia, while another vet declares that "Nah, it doesn't."

So they're definitely not perfect. But they DO ferret out those dogs that ARE detected. Without the tests, the breeder might have unwittingly bred those dogs.

Remember, passing all of the recommended health tests doesn't PROVE that a dog is healthy, because....

Most tests reveal only whether a dog is affected at the time of the test. They don't guarantee that he won't develop that health problem later.

Most tests don't reveal whether a dog is carrying a hidden gene for that disorder, which could be passed along to offspring.

Most tests have a subjective element to them and can be interpreted in slightly different ways.

DNA tests DO reveal whether a dog is affected, a carrier, or completely clear. But there are not many DNA tests. Most breeds have no DNA tests available at all.

So we have to use the tests we have. AND we should be breeding unrelated dogs so that if a dog does carry a defective gene for a specific health problem, the unrelated dog he is bred to is less likely to carry the same defective gene.

A breeder who is taking BOTH of these precautions is a breeder who is serious about his responsibility to produce the healthiest dogs he can.

Testing, then, tells you as much about the breeder as it does about his dogs. It's especially important to find such a breeder because there are many other health problems for which there are no tests at all. All you can do is ask about the occurrence of those problems in the breeder's lines, and breeders who are doing testing for problems that CAN be tested for are more likely to be honest with you about problems that CAN'T be tested for.

How many people DO test their dogs before breeding them?

Sadly, very few.

Let me tell you about an experiment that I did. You may have seen so-called "puppy finder" web sites where people post classified ads offering puppies for sale.

I visited a few of these sites and emailed a total of 65 sellers of Labrador Retriever puppies.

My pleasantly-worded message introduced myself as a prospective buyer looking for a family companion. I asked which health tests they had done on their parent dogs before breeding. In Labs, MINIMUM testing would include having the parents' hips and elbows X-rayed, and having their eyes examined by a canine ophthalmologist.

Of the 65 sellers I emailed, 3 sellers replied that they had puppies available for which ONE parent had been X-rayed for hip dysplasia. Several sellers assured me that their dogs had �health certificates� (which are meaningless) from their vet.

And that's the extent of the health testing all these people had done.

So I turned to the newspaper classifieds. Perhaps these sellers were testing parents before breeding? I visited the Pet Classified sections of major newspapers and called 27 Labrador Retriever ads.

The results?

ONE seller had done hip X-rays on both parents. (But no elbow X-rays or eye exams.) The other 26 sellers had done ZIPPO health testing. Not a thing.

Pet shops? I emailed some, telephoned others. No pet shop, anywhere, had (or could get) a Labrador Retriever puppy whose both parents had been X-rayed for hip and elbow dysplasia and had had their eyes examined and certified healthy by a canine ophthalmologist.

By now you must be thinking: "Boy, it sounds like most puppy sellers are pretty evil people!"

Actually that's not the case. Sure, there are some who don't do health testing because it cuts into their profits. To the puppy miller, the puppy farmer, the puppy broker, puppies are simply a cash crop, a commodity to be bought and sold. These unscrupulous sellers are all over the Internet, they're in the classified ads of your local newspaper, and they're in the classified sections of the dog magazines you can buy on the newsstand.

But the majority of people who breed dogs without doing health-testing are not trying to make profits or save a few bucks. They're well-meaning, most of them.

They simply don't have enough knowledge to be breeding a complex living creature. They should have stuck to loving their dogs instead of meddling with things they know very little about. DNA tests � the wave of the future DNA testing for health problems is just beginning. Eventually researchers will succeed in mapping the entire canine genome (the genetic blueprint of the dog). Then breeders may be able to swab the saliva of any dog and find out exactly which health problems that dog has and which health problems that dog carries. Similarly, owners may be able to simply swab the saliva of a prospective puppy � BEFORE buying � to find out if he has or carries any disease. Unfortunately, that day is not today � nor will it be tomorrow. And even when that day comes, health problems won't be solved, because.... TESTING for health problems can only detect them. It cannot stop them from OCCURRING. Geneticists tell us that even if there was a foolproof DNA test for every current disease in every breed, diseases would continue to occur in purebred dogs. Why? Because breeders would still be breeding related dogs from small closed gene pools. Inbreeding depression would march onward and produce yet another generation of dogs with weaker immune systems than the generation before. So health testing is part of the answer, certainly. But it's number 3 on my list. In my opinion, #1 and #2 are FAR more important. 1. Breed dogs who are as unrelated as possible so that the risk of defective genes matching up is minimized, the risk of inbreeding depression is minimized, and genetic diversity is increased. In most breeds, this would require opening up the Stud Book to allow in more dogs with new and unrelated genes. (This was actually done for Basenjis in the 1990s, when the breed was being decimated by health problems.) It may also mean judicious cross-breeding. You might want to read this online article: Speaking Heresy: A Dispassionate View of Cross-Breeding 2. Breed normal-looking dogs with sound structure. No deformities or exaggerations. That means breeds like the Bulldog have to CHANGE. The rationale that breeders are somehow doing a good thing by �preserving� unhealthy characteristics is absurd. Deformed breeds are not a separate species created by the wisdom of God or Mother Nature. WE created these unhealthy anatomical structures because WE thought they were �cute� and then WE decided that they should be part of the Breed Standard. Having done it doesn't make it right. Now WE can correct our mistakes. In some breeds, the existing gene pool has gotten so bad that there are not enough normal-looking dogs to breed, so again, judicious crossbreeding will be necessary to increase health and soundness, while still retaining enough of the physical and behavioral traits of a breed to clearly distinguish it from other breeds. 3. Test every dog for major health problems BEFORE breeding. If you're online right now, you might want to check out this website: Purebred Dog Breeds into the 21st Century: Achieving Genetic Health for Our Dogs by Dr. Jeffrey Bragg This one's pretty good, too: http://www.angelplace.net/Angel/MedicalScreening.htm by Jim Engel