Demography, heritability and genetic correlation of feline hip dysplasia and response to selection in a health screening programme

Matthew Low,Åsa Ohlsson,Kjell Högström,Per Eksell,Lars Audell,Ulrika Olsson

doi:10.1038/s41598-019-53904-w

Matthew Low, Åsa Ohlsson + Show 4 more

Open Access

https://doi.org/10.1038/s41598-019-53904-w

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Abstract

Feline hip dysplasia (FHD) is a debilitating condition affecting the hip joints of millions of domestic cats worldwide. Despite this, little is known about FHD except that it is relatively common in the large breed Maine Coon. We used 20 years of data from 5038 pedigree-registered Maine Coon cats in a radiographic health screening programme for FHD to determine, for the first time, its heritability, genetic correlation to body mass and response to selection. FHD prevalence was 37.4%, with no sex predilection; however, FHD severity increased with age and body mass. Heritability of the radiographic categories used to classify FHD severity was 0.36 (95%CI: 0.30–0.43). The severity of FHD symptoms was also genetically correlated with body mass (0.285), suggesting that selection for a large body type in this breed concurrently selects for FHD. Support for this was found by following generational responses to selective breeding against FHD. Not only did selective breeding successfully reduce the severity of FHD symptoms in descendants, but these cats were also smaller than their ancestors (−33g per generation). This study highlights the value of breeding programmes against FHD and cautions against breed standards that actively encourage large bodied cats.

Highlights

Feline hip dysplasia (FHD) is a debilitating condition affecting the hip joints of millions of domestic cats worldwide
This allowed us to examine: (1) demographics of hip dysplasia from 5038 Maine Coon cats and its relationship to probable risk factors, (2) response to selective breeding, by looking at the relationship between FHD scores and the number of generations within the selective breeding programme, and (3) the heritability of FHD, by using the linked pedigree to calculate the ratio of additive genetic variance to phenotypic variance
Individuals with a genetic predisposition to be larger than average had higher than average FHD scores because of some genetic linkage between these traits. To confirm this finding and to examine a potential consequence of this genetic correlation, we considered whether selection against FHD within the health screening programme had an incidental effect on body mass

Summary

Introduction

Feline hip dysplasia (FHD) is a debilitating condition affecting the hip joints of millions of domestic cats worldwide. We analysed data collected by the PawPeds FHD Maine Coon health programme and linked these data to the Maine Coon pedigree registry This allowed us to examine: (1) demographics of hip dysplasia from 5038 Maine Coon cats and its relationship to probable risk factors (i.e. sex, age, body mass and year of the health programme), (2) response to selective breeding, by looking at the relationship between FHD scores and the number of generations within the selective breeding programme, and (3) the heritability of FHD, by using the linked pedigree to calculate the ratio of additive genetic variance to phenotypic variance. We examined whether selection against FHD in the health programme

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