Final answer:
Genetic issues in greyhounds were undetected due to selective breeding focused on traits without understanding the health consequences, leading to a narrowed gene pool and prevalence of inherited disorders.
Step-by-step explanation:
Genetic issues in greyhounds went largely undetected until the last decade due to a variety of factors. One major reason is that, historically, selective breeding practices focused primarily on enhancing desirable traits like speed and hunting ability without a comprehensive understanding of the associated health consequences. It is only with the recent advancements in genetics and increased awareness of animal welfare that the negative implications of these practices have been brought to light. For example, continuous inbreeding to achieve certain traits has narrowed the gene pool, resulting in a higher prevalence of inherited disorders. This is also seen in other breeds; in the case of the English bulldog, genetic issues have led to a high proportion of births requiring cesarean sections. Scientific research, including the use of pedigrees in dogs and the study of ancient dog remains, has further revealed the impact of selective breeding on genetic diversity and health.