Final answer:
The presence of numerous health issues in pure-bred dogs is due to 'artificial selection', where humans breed dogs for certain traits, which can lead to a reduction in genetic diversity and increase in inherited disorders.
Step-by-step explanation:
The many veterinary problems observed in pure-bred dogs can largely be attributed to the process of artificial selection employed during domestication.
Throughout this process, humans have selected for specific traits, such as physical characteristics or behaviors that are often extreme or exaggerated compared to what might occur naturally.
This selective pressure can lead to a decrease in genetic diversity and can concentrate harmful genes, leading to inherited health issues. While selecting for certain desired traits, other significant traits related to health and vitality may be inadvertently overlooked or compromised.
The critical issue mentioned here is a result of selective breeding for certain traits without sufficient consideration of the overall genetic health of the animals.