The tame foxes shed during the wrong season, would breed at any time of the year, and the vixens developed neurological problems and began eating their pups. This study illustrates the complexity of genetic changes that can occur when single traits are selected to the extreme. The fact that different domestic animals exhibit similar patterns of physical and behavioral changes has been observed for centuries. Most domestic animals have lost their seasonal pattern of reproduction. They also have changes in their neuroendocrine profiles, have increased fertility, and exhibit piebald white spotting of the hair.
Scientists use the term piebald to refer to areas of pure white hair and pink skin underneath.
In horses, this would include both overo and tobiano patterning. When looking at piebald patches, it's important to differentiate white hair and dark skin found in Arabian horses from white hair and pink skin found in true piebald animals such as Holstein cows and Paint Horses. Socks and blazes are examples of piebald spots in horses. Some animals with large piebald spots on the head and body may have neurological defects similar to the genetic defect known in humans as piebaldism. The piebald condition is linked to defects in both the visual system and in hearing.