Optigen have blood tests available for Samoyeds for the following conditions;
The OptiGen XL-PRA test is a DNA-based test that provides, for the first time, a method to unequivocally identify the X-Linked form of Progressive Retinal Atrophy (XL-PRA) in the Siberian Husky and the Samoyed. This will control the gene frequency in the breed so as to prevent producing puppies affected with the disease.
Normally, the vision receptors in the eyes undergo a continual process of replacement and renewal. But with PRA this process slows and, one day, stops. The night vision receptors are the first to fail, and then, a while later, day vision starts to degenerate.
XL-PRA is a "late-onset" form of PRA. It usually isn't until dogs are three to five years old that the first clinical signs of disease start to manifest. Indeed, deterioration can happen as early as five months of age--but no one notices it. Eventually, though, dog owners see that their pet's eyes have taken on a characteristic "shine." The pupils become increasingly dilated in the attempt to let in yet more light. Dogs develop "tunnel vision." It's like trying to look at the world through a narrow tube.
What's different about the XL form of PRA? First, remember that females have two X--or female--chromosomes. In genetic shorthand, that's XX. Males have one X and one Y, or XY. It's the Y that makes males male
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July, 2008 - OptiGen is offering a new DNA test that identifies the Inherited forms of Retinal Dysplasia associated with OculoSkeletal Dysplasia (OSD) in Labrador Retrievers and Samoyeds. OSD is characterized by short-limbed dwarfism and blindness at an early age. The new OptiGen DNA test for OSD-associated Retinal Dysplasia will allow Labrador Retriever and Samoyed breeders to determine if the retinal folds that are often insignificant in many breeds are correlated to the serious condition of OSD.
There is no problem with breeders availing themselves of these tests as other breeds ROUTINELY have collection clinics thus Samoyed breeders can attend one of these and avail themselves of reduced prices.
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.............The latest Pedigree Dogs Exposed TV programme has really caused a stir. Sadly, a lot of what was said was true, but in some cases blown out of proportion. It is only a matter of time till the UK Samoyed community realises that they are going to have to take some notice of what the Kennel Club is saying as a result of the programme.
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Dwarfism is something that has been around for years.
There are degrees of dwarfism; all dogs do not exhibit all symptoms. It has long been known that Retinal Folds can be associated with it, and that testing dogs with these may reveal affected and carrier dogs/bitches. I have certainly taken a bitch out of a breeding programme due to excessive retinal folds. Now there is a genetic test which means that such arbitrary decisions do not have to be taken, or at least taken on a basis of knowledge.
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SCARF has received word from Optigen (www.optigen.
From the Optigen website :"After extensive research in the
laboratories of Drs. Greg Acland and Gus Aguirre, ACVO diplomates and genetic investigators at Cornell University and the University of Pennsylvania, the mutations responsible for OSD in the Labrador retriever and Samoyed have been identified."
I'd like to add here, that without the bravery shown by a couple of
Samoyed breeders over a decade ago in the US, this mutation would not have been found.
What will this DNA test mean to Samoyed Breeders?
This test will allow breeders to know for certain whether those puppy folds seen at 8 - 12 weeks are linked to the RD associated with dwarfism. And even if your dog is shown to be a carrier - breeders can still breed around the situation by breeding to a clear Samoyed and then testing your future offspring with the DNA test. Within a few generations, all offspring could be clear. (HF note; I would take this statement under advisement; I can see no advantage in breeding from an unhealthy bitch or dog for any reason, but this goes back to the Degree of dwarfism)
Optigen is working with CERF (CERF is the US version of the BVA for eyes) right now about puppies who show the folds and cannot get a CERF number because Labradors and Samoyeds with folds are not cerf-able per current ACVO guidelines. It is Optigen's hope that if the dog
does not CERF due to folds, but they test clear with this DNA test,
that CERF would reissue a clear CERF number for those dogs.
What is the mode of inheritance?
Unlike the XL-PRA gene in Samoyeds, the gene for RD/OSD is NOT sex linked.It is an "autosomal dominant with incomplete penetrance". This means that some carriers will show phenotypical evidence of the disease (like retinal folds) and others will not show folds when they are eye tested (ie., CERF).
However, both types of carriers may pass on the defective gene to
their offspring.
Are all dogs with folds or Retinal Dysplasia carriers of the gene that
causes dwarfism?
No. But this new DNA test will be able to tell you if they
are "normal", "carriers" or "affected" with the gene for RD/OSD.
Note-there are other forms of Retinal Dysplasia/retinal folds which
ARE NOT associated with the dwarfism. This test is ONLY for the RD associated with OSD (dwarfism). To read about the various types of Retinal Dysplasia:
http://www.samoyedh
folds
Can Optigen use the sample I previously submitted for the XL-PRA test to test for RD/OSD?
Yes, in some cases that will be possible if enough of the sample is
left.
Check with Optigen if you have previously submitted samples on your dogs
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This paper is interesting because it confirms what some of us have thought in the past; it is highly likely that our diabetes problems are associated with hypothyroidism and other endocrine problems.
Journal of Small Animal Practice
Volume 49 Issue 1 Page 4-10, January 2008
To cite this article: B. Catchpole, L. J. Kennedy, L. J. Davison, W. E. R.
Ollier (2008)
Canine diabetes mellitus: from phenotype to genotype
Breed differences in susceptibility to diabetes mellitus in dogs suggest an
underlying genetic component to the pathogenesis of the disease. There is
little evidence for an equivalent of human type 2 diabetes in dogs, and it has
been proposed that canine diabetes is more comparable to the type 1 form of
the disease. Certain immune response genes, particularly those encoding major
histocompatibility complex molecules involved in antigen presentation, are
important in determining susceptibility to human type 1 diabetes. We tested the
hypothesis that canine major histocompatibility complex genes (known as the
dog leucocyte antigen) are associated with diabetes in dogs. A total of 530
diabetic dogs and more than 1000 controls were typed for dog leucocyte antigen,
and associations were found with three specific haplotypes. The
DLA-DRB1*009/
the UK dog population. This haplotype is common in diabetes-prone breeds
(Samoyed, cairn terrier and Tibetan terrier) but rare in diabetes-resistant
breeds (boxer, German shepherd dog and golden retriever), which could explain
differences in the prevalence of diabetes in these different breeds. There is
evidence that the DLA-DQA1*001 allele is also associated with hypothyroidism,
suggesting that this could represent a common susceptibility allele for canine
immune-mediated endocrinopathies.
This article is cited by:
Carmel T. Mooney. (2008) Changing face of diagnostic testing in endocrine
disorders. Journal of Small Animal Practice 49:1, 1–2
Summary Abstract and References Full Text Article Full Article PDF
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Copied with permission of the Morris Health Foundation; note this study is nearly complete.
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Mapping Refinement of Quantitative Trait Loci for Canine Hip Dysplasia”
principal investigator: Rory Todhunter, BVSc, PhD, Cornell University
sponsorship not needed
Nearly Complete
Hip dysplasia is one of the most common inherited traits in dogs with an extremely high incidence in some large breeds. It is caused by mutations in multiple genes. In previous studies, investigators discovered the genetic markers that point to the chromosomal regions that harbor the genes that contribute to hip dysplasia. In this study, they will narrow down these regions through additional genetic evaluation. By narrowing the regions that harbor hip dysplasia genes across breeds, they hope to discover the contributing mutations and use that information to design genetic tests that can be used to prevent the propagation of dysplastic dogs.
January 2006
Samoyeds are coming to a crux in England. Type has always come first in the British Show scene. It has for the last 30 years. Movement is not really considered important by most breed judges who know neither conformation or movement. Reach, drive and side gait are missing from a lot of British dogs.
Slipping hocks are prevalent in the breed, as are short necks and straight shoulders. Many dogs put far too much effort into their movement for very little ground covering.
At Smiliesam,we aim to produce sound, healthy dogs. I will not breed from any dog that I do not consider good enough, either for health or type reasons.
We have been hip scoring since the scheme were first started in the UK. With the realisation that there may be a problem in eyes, I have also been having all litters screened and all brood bitches eye tested. Sadly, too few people in the UK do this.
Whelping has been a major problem for a few years now.Numerically our numbers are decreasing. More failures to get bitches in whelp are being reported. More difficulties with whelping, with Inertia, something that has plagues the breed for years, being reported more and more. Hydrops keeps rearing it's head as well. Cleft palettes are still being reported.
Diabetes is an inherited problem in Samoyeds in the UK and the US. Up to now,I have not had a diabetic Samoyed , but see no reason why I should avoid being caught one day. The backgrounds of my dogs go back to the same imports as many UK Samoyeds. I do keep my dogs quite lean which might be one reason I am managing not to activate the disposition. (P.S. 8 months after writing this, Zana went down with Diabetes after a bout of Pancreatitis!)
Without Type, of course, you do not have a breed. Having been to places where type is so ignored that the resultant dogs could be bad Akitas or Siberians, I am very aware that Type can be lost. But we have been breeding for type in the UK for years. It's about time we started breeding for 'Health'.
To conclude, we breed for the 'Total Package'
Don't ignore the bad, don't loose the good!