Original sentence: A common problem with any selectively breed population of animals is the susceptibility to a number of health problems that are not generally experienced by non-pedigreed moggies (mixed-breed cats).Breeds have different origins, some are man made or the result of mutation, while others are found in nature.This danger is primarily the result of inbreeding, and professional breeders have to take great care to eliminate sick individuals from the breeding population in order to insure the health of the breed as a whole
Edited sentence: A popular misconception is that pedigreed cats are prone to a number of health problems that are not generally experienced by non-pedigreed moggies (mixed-breed cats).Breeds have different origins, some are manmade or the result of mutation, while others are found in nature.Certainly the genetic base for many breeds is quite small and inbreeding occurs.However, ethical breeders select for healthy animals as those with major health problems do not survive long or contribute to the long term welfare of the breed