OBJECTIVE: To determine mortality rate over time, risk factors for death, and heritability of life expectancy in Boxers. ANIMALS: 1,733 purebred Boxers born in The Netherlands between January 1994 and March 1995. PROCEDURE: Dogs were followed up from weaning (ie, 49 days of age) to 10 years of age through use of a written questionnaire sent to owners every 6 months. Mortality rate over time, risk factors potentially associated with death, and heritability of life expectancy were examined by use of a proportional hazards model based on the Weibull distribution. RESULTS: stimated mortality rate during the 10-year study period for this birth cohort of Boxers was 45%. The probability of surviving to 5 years of age was 88%; the probability of surviving to 10 years of age was 55%. Estimated effective heritability of life expectancy was 0.076, meaning that in this population, an estimated 76% of the observed variation in life expectancy could be attributed to genetic differences among dogs that were passed from parents to their offspring. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that cumulative incidence of death from weaning to 10 years of age among this birth cohort of Boxers was 45%. The estimated heritability of life expectancy suggested that life expectancy can be improved by use of selective breeding.
OBJECTIVE: To determine mortality rate over time, risk factors for death, and heritability of life expectancy in Boxers. ANIMALS: 1,733 purebred Boxers born in The Netherlands between January 1994 and March 1995. PROCEDURE: Dogs were followed up from weaning (ie, 49 days of age) to 10 years of age through use of a written questionnaire sent to owners every 6 months. Mortality rate over time, risk factors potentially associated with death, and heritability of life expectancy were examined by use of a proportional hazards model based on the Weibull distribution. RESULTS: stimated mortality rate during the 10-year study period for this birth cohort of Boxers was 45%. The probability of surviving to 5 years of age was 88%; the probability of surviving to 10 years of age was 55%. Estimated effective heritability of life expectancy was 0.076, meaning that in this population, an estimated 76% of the observed variation in life expectancy could be attributed to genetic differences among dogs that were passed from parents to their offspring. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that cumulative incidence of death from weaning to 10 years of age among this birth cohort of Boxers was 45%. The estimated heritability of life expectancy suggested that life expectancy can be improved by use of selective breeding.
Authors: Dan G O'Neill; Nicola J Rooney; Callum Brock; David B Church; Dave C Brodbelt; Camilla Pegram Journal: Canine Genet Epidemiol Date: 2019-06-04