According to the Vipoodle Health Organization regarding types of genetic testing for dogs, “there is a big difference in types of testing. They warn that very few of their tests measure genotype (actual DNA sequence of a gene). Most of the tests only measure phenotype (a physical evaluation). Phenotype testing they say, “provides less reliable information about the genes a given dog might pass on to offspring.” They also suggest that, with many of these tests, you repeat them yearly to see if your dog has developed the disease yet.
If most of the information received from these tests isn’t very reliable in terms of assurance that my dog doesn’t have the disease, won’t develop it eventually, or that it won’t be passed on to future generations of puppies, then what is the purpose of putting my dog through all of the discomfort and possible harm from certain genetic testing?
I was perplexed by this. Why do some breeders stake their reputation on the results of these tests if the tests have very little meaning? I decided to get a first hand opinion from someone who has been on both sides of the issue.
I interviewed someone who is not only a veteran breeder, but also a trained Vet Technician who has been working in these fields for 13 years. This Vet Tech has both assisted Vetrenarians during these tests and also initially had them done to her own breeding dogs.
Even though she used to have certain genetic test done on her own dogs, she no longer does. I asked, “Why, if you used to do them, did you now feel they are no longer useful?” She explained that, as a Vet Tech, she had been trained to do them without questioning the process and without doing her own research into their usefulness, their safety, or lack thereof.
After having been away from the influence of the clinic and diving into research, she is now more mindful of the pros and cons of genetic dog tests and admitted that the tests were, in terms of results, both unneccessary and worse, highly subjective (meaning the results depended on the mood of the person doing them). Her focus as a breeder, is now on nutrition and prevention of disease, rather then tests that neither prevent, or help support the cure of the diseases.
Hip Dysplasia (HD)
Hip dysplasia, as described by the medical industry, is an “inherited disease that manifests in a malformation of the hip joint in which the ball and socket do not properly fit together. It is believed that mildly dysplastic dogs may not exhibit any outward signs. Moderate to severe cases may exhibit rear-end lameness and/or discomfort when getting up. Young dogs, five to ten months, may be affected, and older dogs may develop chronic degenerative joint disease.” (4)
The test is done by X-ray at 24+ months for OFA hip certification, at 16+ weeks (4 months!) for PennHIP scores (although a more accurate score may be obtained at six months, or even twelve months they say). After X-raying your dog’s hips, the films are sent to the OFA registry for a reading. Although that is the standard course for testing by the medical industry, some more natural minded veterinarians believe it may be incorrect.
According to Wendell O. Belfield, DVM, who researched the role nutrition played on hip dysplasia, hip dysplasia is more likely to be the result of malnutrition, and can be resolved with good nutrition. Keep in mind there is little to no nutrition information taught in veterinary school. If your dog is not adequately nourished or if he comes from malnourished parent lines, he is more likely to develop bone and joint problems according to Belfield.
During his many years as a veterinarian, Dr. Belfield saw hip dysplasia improve in old dogs, disappear in younger dogs and in breeding females that once had litters of puppies with this problem. This stopped occuring once their nutrition was improved. (3)
Again, I spoke with the former Vet Tech (mentioned above) to get her opinion about this test. She no longer does this test, and is concerned that it’s not only unneccessary, but it also has the potential to damage the hips of the dog. She explained that the test not only involves having your dog exposed to anesthesia which always carries a danger, but also the hips are forcibly dislocated. This causes both shock and trauma to the joint. Next, the dogs are exposed to X-ray radiation (more damage) so that a radiologist can measure the distance of how far the ball goes out of the socket. All of this risk and potential damage to the dog’s hips and surrounding tissues just to measure the distance between the hip and how far it was dislocated. In addition to this, in the Vet Tech’s opinion, “even though a certified radiologist does it, it is very subjective – depending on who does it, and the day.”
What does radiation do to the reproductive system? In addition to the kind of damage X-ray causes to the bones and socket of the hips, these are breeding dogs being exposed to radiation. We know that one exposure to X-ray gives the body the equilivent of 10 days worth of radiation exposure. Because the bones are rich in calcium, which has a high atomic number, the radiation from an X-ray is readily absorbed into them. The adjoining tissue in the case of hip X-rays is the entire reproductive system. The reproductive system is believed to suffer a lesser harm than the hip bones do from radiation exposure, but that remains yet to be proven. (2)
What is the potential damage to my dog’s hips from x-ray radiation? The radiation we get from an X-ray is called ionizing radiation. Ionizing radiation is a high-energy wavelength, or particles, that penetrate tissue. Ionizing radiation is the type that comes from radioactive substances that detach electrons from atoms and molecules. It can therefore damage DNA. However, if you are healthy, have adequate minerals in your diet, and are active then your cells may repair most of the damage, but this is not always the case, and the bones can heal inadequately. According to Harvard Health, “The result [of x-ray radiation] is DNA mutations that may contribute to cancer years down the road.” (1)
This potential harm to living tissue is what landed X-rays in the class of a carcinogen (causes cancer). Receiving X-rays is a risk that increases with the number of X-ray exposure over time. The medical field believes that for them, it is “worth the risk” on your body, so they can benefit and possibly make a more accurate diagnosis; however, truly you have to decide if the benefits outweigh the risk for yourself in your individual situation. Nonetheless, all radiation (regardless of the source) interrupts the communication between the cells of the body and the brain. Whether the body is able to repair itself after exposure, or to what extent it repairs, is up to the individual’s body. (1),(2)
Most people are unaware that radiation current is cumulative, meaning it accumulates in the body while you are being exposed. Therefore, how often you are exposed, as well as for how long, are both important in terms of risk and potential damage. People exposed to high amounts of electromagnetic fields (EMFs) are more likely to develop leukemia and other cancers, according to. The same applies to dogs. The younger they are, during growing stages, the more potential for damage. (5)
In summary, genotype (actual DNA sequence of a gene) and phenotype (a physical evaluation / clinical impression) are not the same. Most of the dog genetic health tests measure phenotype, and this provides less reliable information about the genes a given dog might pass to offspring. Essentially this means the test results are at the mercy of the one doing the testing, and may change as the dog’s nutrition and/or environment changes. (6)
- How To Have a Healthier Dog, Wendell O.Belfield DVM, and Martin Zucker, Doubleday and Company, Inc.,1981
- December, 1980, EPA study “Evaluation of the Potential Carcinogenicity of Electromagnetic Fields.”
Additional information about how to both protect the body from radiation and to rid the body of radiation:
- Electromagnetic Fields: A Consumer’s Guide to the Issues and How to Protect Ourselves, by B. Blake Levitt
- Earthing, The most important health discovery ever? By Ober, Sinatra, and Zucker