London's Imperial College: Extent of inbreeding in pedigree dogs revealed in new study, 2008-Aug-15, by Laura Gallagher :
Although the problems associated with inbreeding have been known for many years, prior to the new study it had not been systematically measured. For this study, researchers from Imperial used mathematical modelling to analyse how dogs were related to one another within ten different dog breeds including the Boxer and Rough Collie.
They looked at the parentage of eight generations of dogs, using records collected from 1970 to the present day by the UK Kennel Club.
The researchers' analysis showed that, for example, Boxer dogs were so closely related to one another and had such little genetic variation between them that genetically, 20,000 dogs looked like a population of about 70. In the Rough Collie breed, 12,000 dogs looked in genetic terms like a population of about 50.
Such small effective population sizes mean that the chances of a dog breeding with a close relative, resulting in birth defects and genetically inherited health problems, are high.
Comments