Coat Hair Length Testing

Understanding Coat Genetics

 

The correct mastiff coat is short, close-lying, and weather-resistant. However, like many breeds, mastiffs can carry a recessive gene responsible for long hair.

 

Coat length is controlled by the FGF5 gene, which exists in two forms:

 

• Dominant gene – produces the correct short coat

• Recessive gene – produces long hair when inherited from both parents

 

A mastiff may appear entirely correct in coat while still carrying the recessive gene unseen.

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Why Coat Testing Matters

 

While coat length does not impact health, it plays a vital role in breed integrity.

 

At Womlu Mastiffs, coat testing supports:

 

Preservation of Breed Type

 

The short coat is part of the mastiff’s historical and functional identity. Producing long-coated dogs moves away from the recognised standard.

 

Informed and Ethical Breeding

 

DNA testing removes uncertainty. It allows breeders to make deliberate, educated decisions rather than relying on chance.

 

Consistency and Predictability

 

Two carriers bred together may produce long-coated puppies. Testing ensures this outcome is understood—and avoided where desired.

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Inheritance Explained

 

Coat length follows a simple recessive pattern:

 

• Clear × Clear

    All puppies short-coated, no carriers

• Carrier × Clear

    All puppies short-coated, some carriers

• Carrier × Carrier

    Risk of long-coated puppies

• Carrier × Long-coated

    Increased likelihood of long-coated puppies

 

Understanding this allows breeders to plan responsibly while maintaining genetic diversity.

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Our Position on Long-Coated Mastiffs

 

A long-coated mastiff is not inferior in health or temperament—it remains every bit a mastiff in character.

 

However:

 

• It does not meet the breed standard

• It is not suitable for showing

• It should not be intentionally produced

 

Our focus remains firmly on preserving the traditional mastiff as it was intended.

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The Testing Process

 

Coat length testing is simple and reliable:

 

• A cheek swab or blood sample is taken

• Submitted to a recognised laboratory

• Results identify the dog as:

  • Clear

  • Carrier

  • Long-coated (affected)

 

This is a one-time test, providing lifelong clarity.

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A Balanced Approach to Breeding

 

At Womlu Mastiffs, we believe coat testing should support—not dominate—breeding decisions.

 

Our priorities remain:

 

• Sound health

• Correct temperament

• Strong, functional structure

• True mastiff type

 

Genetic testing is a tool, not a replacement for experience, knowledge, and dedication to the breed

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