The Importance of Comprehensive Breeder DNA testing, tools and services, and COI for your breeding programs

Genetic health testing is an integral part of a sound dog breeding program. A comprehensive full-panel test leaves no stone unturned and lets you identify ‘clear,’ ‘carrier,’ and ‘at-risk’ designations for all breed-relevant conditions. Your dog’s genome is checked for variants that may put your dog, or offspring, at risk for disease.

For example, there are 20 breed-relevant genetic health conditions for the Labrador Retriever. The most common health risk, Stargardt Disease (ABCA4 Exon 28, Labrador Retriever Variant). Stargardt Disease is a non-painful inherited degenerative disorder of the rod and cone photoreceptor cells of the retina that results in vision loss. Rods affect vision in the dark, or low light, and cones affect vision in light. As the disease progresses, cone function is profoundly abnormal, whereas rod function is better preserved. Vision slowly deteriorates, but some vision remains throughout an affected dog’s lifetime. The mode of inheritance is recessive.

• Based on Embark-tested Labrador Retrievers that have opted into research, here’s a snapshot of the breed today: 79.1% of dogs tested clear, 18.8% tested carriers, and 1.3% tested at-risk for Stargardt Disease.

Citations: Makelainen et al 2019 Ekesten et al 2022

Beyond breed-relevant testing, genetic health screening can provide detailed information to improve your dog’s health, optimize breeding pairs, improve litter outcomes, and contribute to longer lifespans in your breeding lines. A genetic health screen does not eliminate the need for a veterinary health exam to detect health issues, but it is crucial for detecting genetic defects that could manifest as a disease later in life or could be passed onto offspring if a dog is bred.

Coefficient of Inbreeding

Many factors are considered when choosing which dogs to use in breeding programs including conformation, temperament, genetic diseases, and more. Assessing the impact of inbreeding should be another factor.

Studies show that excessive inbreeding can have a profound impact on a dog’s health and lifespan. Many breeding programs utilize linebreeding and inbreeding as a means of maintaining breed characteristics and emphasizing desired traits. However, as inbreeding increases in a breed so do some negative effects, such as reduction of litter size, reduced fertility, decreased disease resistance, and failure to thrive in puppies.

Genetic coefficient of inbreeding (COI) is the most accurate method for measuring inbreeding. Unlike pedigree-based COI calculations, genetic COI evaluates the actual pieces of DNA in your dog to identify which proportion traces back to inbreeding.

Pedigree and genetic-based COI scores are not interchangeable—they can vary widely. Pedigrees usually go back 5-10 generations to detect recent inbreeding, but they assume the dogs at the beginning of the pedigree are all unrelated, which isn’t an accurate assumption for most dog breeds. Pedigree scores assume all puppies inherit an even DNA distribution from both parents across all chromosomes. But in reality, generations of breeding create more randomized outcomes. Factoring genetic COI into your breeding program can help you minimize inbreeding.

Accurate determination of inbreeding tracts is crucial for identifying recessive disease mutations through homozygosity mapping. It is also for more precisely understanding the risks of inbreeding within and across breeds. Although some level of inbreeding cannot be avoided for most purebred dog breeds, and inbreeding risk shouldn’t be the only consideration when selecting mates, reducing the inbreeding load in a population is a valuable goal.

As a responsible breeder committed to the long-term health and longevity of your dogs, you may want to consider adding genetic health screening to your breeding program. You’ll join other breeders working to breed happy, healthy dogs. As an ADI Corporate Partner, Embark is offering a complimentary Embark for Breeders Dog DNA Test to all ADI North America and Europe members. To obtain your complimentary test, please contact [email protected].

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Award-winning writer, journalist, and podcast host, Lisa Peterson, is a canine subject matter expert and Content Strategy Lead at Embark Veterinary. 

She served as the American Kennel Club director of communications and club communications before becoming a Westminster Kennel Club public relations consultant. Lisa began owning, breeding, and handling Norwegian Elkhounds more than 35 years ago, and today is an AKC judge and AKC Breeder of Merit. She also is an AKC national spokesperson, having made hundreds of regular guest appearances on television and radio.

Lisa bred generations of champion dogs, including multiple-specialty best in show winners and top award winners at national specialities in the U.S. and Canada. She is president of the Garden State Norwegian Elkhound Club, a member of the Norwegian Elkhound Association of America, and the Newtown Kennel Club. 

Lisa holds a Bachelor of Arts in political science/journalism from the University of Bridgeport, and a Master of Fine Arts in creative and professional writing from Western Connecticut State University.