I should have scanned past it like I do with most other posts, but I saw an opportunity to answer what I thought was a genuine query, so took a quick moment to engage. We only recommend products we use and genuinely love.Ī few months back, I happened upon a post online in a dog training group in which I occasionally participate. Mixed breed dogs, are often the result of random matings that are usually not controlled, and are therefore still suffering from these diseases.Disclaimer: this article contains affiliate links, and we may receive a commission on sales when you use those links, at no additional cost to you. Conscientious dog breeders systematically eliminate dogs which have shown genetically based diseases from their breeding programs and also take advantage of genetic screening tests that have become available in recent years. The disappearance of these diseases in such purebred dogs is really based on the efforts of breeders. Similarly, a genetic disorder which leads to blindness and neural system collapse in Border Collies (neuronal ceroid lipofuscinosis) and a severe combined immunodeficiency disease, originally found in Basset hounds, have been eradicated in pedigreed lines. For example, Beagles were susceptible to a severe anemic disease (pyruvate kinase deficiency), which through careful screening of pedigrees and genetic testing has been completely eliminated in the breed but not in mixed breed dogs. Thus some canine diseases known to have genetic basis have been virtually eliminated in purebred dogs but are still sorting their way through mixed breed populations. The investigators note that breeders may actually have been producing healthier dogs over time. One particularly interesting finding in this research directly relates to the media charges that dog breeders are deliberately perpetuating lines of genetically unsound dogs. Thus if an individual appears in a medical facility showing symptoms of sickle cell anemia it is a good bet that both of his or her parents are of African descent, while an individual showing symptoms of Tay-Sachs disease will most likely have two Jewish parents. Among Jewish individuals living in the United States the estimates are that that 1 in every 27 carries the allele. A similar situation appears in the case of Tay-Sachs Disease, which is most common in Jewish individuals. Data shows that 1 in 12 African-Americans carry the sickle cell allele, so any mating between two individuals in this group would increase the probability that their offspring might have the disease. Well-known examples of inherited diseases associated with genetic lineages include Sickle Cell Anemia which is most common in individuals of African ancestry. Since humans tend to marry individuals who are of their same race and religion it means that we are essentially engaged in a limited form of interbreeding. We see examples of this in human populations. Since pedigreed dogs are interbred with other dogs that can trace back to the same ancestry, this clearly predicts that purebreds should be more likely to suffer from inherited diseases than mixed breed dogs. On the other hand, if you have breedings from outside of this lineage (hybrids) the chances are much less. So if you have a line of related individuals that tend to have that allele and they interbreed, the chances that you will get two copies of the defective gene are greatly increased, meaning that many of the offspring will have that genetic disease. (Think of an allele as one of two alternate forms of a gene.) However, in many other instances, we are dealing with a "recessive" disease which will only appear if you get two of the defective alleles (one from the father and one from the mother).
For certain genetically caused diseases, all you need is one defective allele in order for the disease to show up. The genetics behind this are really quite simple. Source: Photo by Pets Adviser from Brooklyn, USA Creative Commons Attribution 2.0 Licenseįor as long as I remember it has been argued that mixed breed dogs are healthier than purebred dogs because of "hybrid vigor".
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