Genetic Testing
Genetic testing can help reduce the risk of passing on inherited conditions to puppies. In the border collie breed, there are over a dozen breed-relevant conditions that we know at present. This is continuously evolving as new markers are found. One of our goals is to stay up to date with testing our dogs to prevent avoidable health conditions. Below is a list of the current known genetic conditions that can affect border collies.
What tests, and why?
Every dog genetic panel out there will test for certain genes and conditions. At present, the only panel that tests for the Early Adult Onset Deafness (EAOD) complete markers is Optimal Selection. Unfortunately, this panel does not cover Border Collie Glaucoma (BCG). Therefore, we use multiple panels to cover testing for all breed conditions. All of our dogs are currently tested with Optimal Selection as well as at least one additional panel, such as Embark DNA, Animal Genetics, or AKC Health, to be thorough with genetic testing. We will never breed carriers together or intentionally produce at-risk dogs. Thank you to Heather Tetzlaff for creating this table to compare genetic panels and to provide insight as to why we choose the panels we do to test for breed relevant diseases.
Genetic Testing Panels
Our breeding stock are tested through Optimal Selection + 1 other lab to account for all breed-relevant genetic diseases. We do not breed carriers to carriers in order to eliminate the chances of producing puppies affected with testable health issues. The graphic provided explains the inheritance of recessive alleles.
Early Adult Onset Deafness (EAOD)
Resources for this unmapped gene.
"In partnership with University of Helsinki and Dr. Hannes Lohi’s research laboratory, Wisdom Panel is pleased to offer a four marker risk panel for early adult onset deafness (EAOD) in the Border collie in its Optimal Selection™ Canine and MyDogDNA® tests. This disorder is devastating in that it causes hearing impairment or deafness in otherwise healthy adult dogs, usually diagnosed between the ages of 4 and 7 years, rendering traditional herding work difficult or impossible for them to perform, and often after they have produced puppies. This test is being offered before peer-reviewed publication in partnership with the primary researchers to expedite the search for the causative gene, and because the disorder is common and of great concern to the Border collie community." (Wisdom Panel, 2021)
Recommended guidelines for navigating EAOD.
"Wisdom Panel, University of Helsinki, ABCA and ABCA HEF are aligned in the following recommendations for breeding programs:
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Breedings should be planned so that no at risk genotype dogs are produced...
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Carriers: It is most responsible to continue to use carriers in your breeding programs assuming the dogs are otherwise excellent examples of the breed, but care must be taken to breed them to normal hearing, clear genotype dogs...
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At risk dogs: At risk genotype dogs can also continue to be used in breeding programs if they are otherwise excellent examples of the breed, but care must be taken to breed them to normal hearing, clear genotype dogs so no at-risk puppies are produced.
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Puppies: All puppies of parents who tested as carrier or at risk genotype should be tested, as litters will likely have both carrier and clear genotypes present, and testing one puppy will not be representative of the whole litter.
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Clear by parentage: As with other types of disorders, it is wise to check breeding dogs assumed to be clear by parentage every few generations." (Wisdom Panel, 2021)
Read more information about EAOD in the articles linked below. BAER hearing testing is encouraged in breeding dogs and litters to aid in the research for finding the causative gene of EAOD in border collies. At this point, Optimal Selection (Wisdom Panel) is the most comprehensive EAOD panel and should be used to test breeding stock over other panels, such as Orivet.
Border Collie Glaucoma (BCG)
Recommended guidelines for navigating BCG.
"There were too few glaucoma cases in our study to allow identification of loci involved in progression from goniodysgenesis to glaucoma in the Border Collie and ambiguous phenotyping complicates the investigation of mild goniodysgenesis. The genetic relationship between the mild forms and the more severe forms is unknown, but the OLFML3 variant described here does not appear to be associated with most cases of mild goniodysgenesis indicating that genetic predisposition to mild goniodysgenesis may be independent of the findings of this study. Although testing for the OLFML3 variant (whether it is causative or in linkage disequilibrium with the causative DNA variant) would allow breeders to select against homozygotes to decrease the prevalence of the risk genotype for severe goniodysgenesis, it is important not to reduce the breeding pool too much because of the risk of other recessive conditions resulting from homozygosity for alleles that are identical by descent. Although we need to understand why some goniodysgenesis cases progressed to glaucoma at a young age and some do not, before we can make firm recommendations to the breeders of Border Collies worldwide, we suggest that following DNA testing dogs of all genotypes could be used provided at least one partner in the mating is homozygous for the wild type allele. This would ensure that no homozygotes for the risk allele were produced. We would strongly advocate that efforts be made to maintain the breadth of the gene pool by not avoiding the use of animals that carry this variant. As discussed previously (Farrell et al. 2015), strong selection away from variants serves to narrow genetic variability and can give rise to future health problems. All breeding decisions should be made with this, and the wider health of the breed, in mind." (Pugh et al. 2019)
"Regardless of whether the OLFML3 variant is causative of PLA and PCAG or not, a DNA test based on this variant can still be used effectively to reduce disease prevalence. This is because, even if the tested variant is not responsible for PLA and PCAG, the true causative variant is likely to be located very close to it on chromosome 17 and, therefore, will be genetically linked to it. In this situation, a DNA test based on the OLFML3 variant would be acting as a linkage test which, although less reliable than a mutation detection test, would still have good sensitivity and specificity.
Selective breeding based on DNA test results would allow the variant to be eliminated from the population easily and quickly. DNA testing should, however, be accompanied by breeding advice with the aim of reducing disease prevalence but not at the expense of reducing genetic diversity. Because PLA and PCAG in this breed appear to be mainly acting as monogenic autosomal recessive traits, dogs both heterozygous and homozygous for the variant can be used in breeding programs as long as mated with dogs homozygous for the wild‐type allele. This approach will lead to a gradual reduction in the prevalence of the variant without the risk of creating dogs homozygous for the variant and thus being at risk of developing PLA and PCAG. It is important to emphasize, however, that, although PLA is a recognized risk factor for PCAG, only a minority of dogs with PLA develop PCAG. It is also very likely that other genetic and environmental factors are involved in PLA and PCAG pathogenesis, and thus, it is important that dogs continue to be clinically phenotyped by serial ophthalmic examinations including gonioscopy regardless of their genotype for the OLFML3 variant." (Oliver et al. 2019)
Pugh CA, Farrell LL, Carlisle AJ, Bush SJ, Ewing A, Trejo-Reveles V, Matika O, de Kloet A, Walsh C, Bishop SC, Prendergast JGD, Rainger J, Schoenebeck JJ, Summers KM. Arginine to Glutamine Variant in Olfactomedin Like 3 (OLFML3) Is a Candidate for Severe Goniodysgenesis and Glaucoma in the Border Collie Dog Breed. G3 (Bethesda). 2019 Mar 7;9(3):943-954. doi: 10.1534/g3.118.200944. PMID: 30696701; PMCID: PMC6404605.
Oliver JAC, Wright H, Massidda PA, Burmeister LM, Mellersh CS. A variant in OLFML3 is associated with pectinate ligament abnormality and primary closed‐angle glaucoma in Border Collies from the United Kingdom. Vet Ophthalmol. 2020;23:25–36. https ://doi.org/10.1111/vop.12680
More information.
Presently, Optimal Selection does not include testing for the OLMFL3 gene as a part of the genetic disease panel. Therefore, it is recommended to add an additional panel for border collie breeding stock to be comprehensive and thorough in genetic testing. Below are some options for companies that test for BCG OLMFL3 gene. The test is currently not accurately predictive, meaning that "affected" dogs (dogs that carry two copies of this gene) may not develop glaucoma. However, we err on the side of caution and do not breed carriers to carriers and hope that one day the research will continue to create a more accurate test.