Use of cross-country data for estimation of heritability of longevity and heart-related deaths in Doberman Pinscher

Presenter Joanna Ilska
Authors Joanna J. Ilska (1), Paolo Gottardo (2), John Hickey (1), Dylan N. Clements (3)
Affiliations 1. The Roslin Institute and Royal (Dick) School of Veterinary Studies 2. Italian Brown Swiss Breeding Association, Italy 3. Royal (Dick) School of Veterinary Studies and The Roslin Institute
Presentation Type Talk


Genetic improvement with the use of Estimated Breeding Values (EBV) is a method which, after decades of successful and validated use in livestock species, slowly gains recognition in the world of dogs breeding. However, accurate EBV prediction for complex traits requires large datasets of phenotyped and related animals. While generation of such datasets is possible in the most popular dog breeds, for many other breeds reaching sufficient numbers within any national database is not likely. Further, collection of the data pertaining to diseases through national Kennel Clubs is usually limited to very few already established grading systems for specific diseases, such as British Veterinary Association’s scheme for Hip and Elbow Dysplasia. Thus, databases created by independent breed societies combining records across countries and on breed-specific issues, could become sources of data for the genetic analyses and EBV predictions in numerically small breeds.
We present a preliminary analysis of the heritability of longevity and heart-related deaths (HEART) in Doberman Pinscher, based on data collated by The Doberman Welfare Community (DWC) – an independent group of breed enthusiasts. The data included over 350,000 dogs over 37 generations, born between 1890 and 2017, and from 18 geographical regions. Phenotypic records on longevity and cause of death were recorded for 10,549 and 5,844 dogs respectively. Among the causes of death, HEART were most common (48%), and more frequent in males than females (55% males, 45% females). The average longevity (LONG – number of months between birth and death) was 89 months for males and 100 months for females.
A number of mixed linear models were fitted to identify significant environmental factors affecting LONG and HEART, and to estimate heritability of the traits. LONG was Box-Cox transformed to improve normality of the data, and binomial models were fitted for the heritability estimation of the underlying liability for the HEART. Factors identified as significant for HEART were sex, region, season of birth, and year of death. LONG was affected by year and season of birth, as well as year of death. Heritability of the HEART and LONG was 0.29 ( 0.02) and 0.11 ( 0.02) respectively.
To the best of our knowledge, these are the first published estimates of heritability of longevity and heart-related deaths in Dobermans using owner-collated data. A significant genetic variance detected for both traits indicates that selection could bring improvement in these traits, which is particularly important for HEART – heart conditions are believed to affect as many as 20% of Dobermans, and the symptoms of the disease often appear after a dog has already been used for breeding. Neither longevity nor causes of death are typically recorded by national kennel clubs, thus highlighting the role of societies such as the DWC in collecting this type of data. Further, significant estimates obtained in the presented analyses indicate validity of the data, thus opening a new window of opportunity for genetic analyses of complex traits in numerically small breeds through the recruitment and collation of data by breed enthusiasts.