Using Dog Health Records in Genome Wide Association Studies to Improve Breeding Outcomes

The Seeing Eye’s stated mission is to enhance the independence, dignity and self-confidence of people who are blind, through use of specially trained Seeing Eye® dogs.

In pursuit of this mission, The Seeing Eye, based in Morristown, NJ, breeds and raises puppies to become Seeing Eye dogs, trains dogs to guide vision impaired people, instructs people in the proper use, handling, and care of the dogs and conducts and supports research on canine health and development.

IWDA member Dr. Katy Evans, the Jane H. Booker Chair in Canine Genetics and presenter at IWDC 2021, performed a study with Nicole Anclade, Ariella Miller, Liam Haller, Dr. Delores Holle and Peggy Gibson at Cornell University’s Odyssey DNA Lab, aiming to evaluate canine traits that would assist in breeding both better Seeing Eye Dogs and working dogs in general.

“We had a lot of interesting observations, but there is more we need to do in adding another tool to our breeding toolbox,” Evans said during her IWDC presentation.

A dataset of over 220,000 genetic markers spanning the canine genome has been compiled for over 1,000 dogs to date at The Seeing Eye with the intention of using genomic markers to inform selection and management decisions. 

Dogs genotyped include current and former breeders, birth cohorts of individual breeds (German Shepherds, Labrador Retrievers, Golden Retrievers and Labrador/Golden Retriever crosses) and cases and controls of some specific conditions. These genotypes were used in genome-wide association studies (GWAS) for health traits for which dogs could confidently be assigned as cases or controls.

GWAS for 37 health traits were performed, the breakdown of which is: dental (13), ocular (8), dermatologic (7), orthopedic (2), gastrointestinal (4), connective tissue (1), cartilaginous (1), and muscular (1).  Genomic principal component analysis was conducted to validate individual breed designation and overall population structure. 

The current GWAS highlighted SNPs potentially influencing traits in multiple breeds whereas future studies will seek breed specific associations

Of the traits passing multiple testing corrections, nine were dental, seven were ocular, one was orthopedic, four were dermatologic, one was muscular, and one was cartilaginous. Evans pointed out three which could affect future breeding at The Seeing Eye:

  • Distichiasis, which is a condition in which a dog’s eyelashes develop in an abnormal location, emerging from the eyelid margin rather than the eyelid skin. This can cause corneal ulcers and might have to be corrected by surgery or laser treatment.
  • Atopic or Allergic Dermatitis, which can cause various symptoms such as skin irritation and conjunctivitis and precludes such dogs from breeding.
  • Panosteitis, a painful inflammation of the outer surface or shaft of one or more long bones of the legs. It sometimes resolves by itself, but supportive treatments such as analgesics are often needed.

Access to studies using large and specific data sets like this are integral to improving breeding outcomes for working dog organizations. For example, Estimated Breeding Values rely on available data within a breed in order to provide enough information to effectively assist in breeding decisions.

 

by Jed Weisberger