Selective breeding of dogs

摘要

From an early age I have owned and been owned, by many dogs. Most of these have been what we describe as pedigree dogs including German Shepherds, Rottweilers, Labradors, and Yorkshire Terriers but also a number of cross-breeds (mongrels).Over the years I have noticed that breeds have changed with not only dogs going in and out of 'fashion' but with also many breeds I am familiar with experiencing health problems, that 30 years ago, did not exist to the extent they do now.