It's not a matter of the ears *turning* black, but rather a characteristic of the breed. The black pigment is determined by genetics and is present from birth.
Here's a breakdown:
* Genetics: The color of a Yorkshire Terrier's coat, including their ears, is determined by genes inherited from their parents. These genes dictate the presence and distribution of melanin, the pigment responsible for color.
* Coat Color: Yorkies are known for their long, silky, blue and tan coat. While the body fur is typically blue (a steel-grey color), the ears, muzzle, legs, and feet are typically tan. The ears are always black, regardless of the overall coat color.
* No Change: The color of a Yorkie's ears doesn't change over time. However, as the dog ages, the tan color may fade slightly, making the black ears appear even more prominent.
If you notice any drastic color changes in your Yorkie's ears, it's always best to consult with a veterinarian to rule out any underlying health conditions.