Here's why:
* Size Disparity: German Shepherds are large dogs (typically 65-90 pounds), while Yorkies are tiny (4-7 pounds). This significant size difference would make breeding physically impossible.
* Physical Differences: Their body structures are also vastly different, making it difficult for them to physically align for mating.
* Health Risks: Even if breeding were somehow possible, it would likely lead to serious health problems for both the mother and offspring. The puppies would be much too large for the Yorkie mother to carry and give birth to safely.
It is important to note that breeding dogs that are very different in size is generally discouraged, as it can result in health issues and other complications. It's best to choose dogs that are within the same breed or similar in size for responsible breeding.