They are a breed that is traditionally docked, meaning their tails are surgically shortened shortly after birth. This practice is done for a number of reasons, including:
* Preventing injuries: Terriers, being working dogs, are prone to tail injuries.
* Aesthetics: The short tail is part of the breed standard for Toy Fox Terriers.
* Historically: Tail docking was common practice for working dogs to prevent them from being caught on things while working.
However, it's important to note that:
* Tail docking is now controversial: Many people consider it to be a painful and unnecessary procedure.
* Not all Toy Fox Terriers are docked: Some breeders choose not to dock their puppies' tails.
* Natural tails are becoming more common: The trend in responsible breeding is moving towards leaving tails intact.
So, to answer your question directly: While a Toy Fox Terrier might be born with a short tail, it's usually the result of docking, not natural genetics.