top of page

Fact vs. Fiction: Understanding Coat Quality in Chihuahua Breeding

Ch. A & A's The Dapper Don " Royce"

Both parents are smooth-coated

As breeders, we strive to make informed decisions based on genetics to maintain the integrity and quality of our Chihuahuas. One persistent myth is that breeding two smooth-coated Chihuahuas can result in poorly coated,

long-coated offspring. This is not only misleading but also scientifically inaccurate. Let’s dive into the genetics and real-world data to debunk this myth once and for all.

Understanding the Genetics of Chihuahua Coat Traits

Chihuahua coat types and quality are determined by multiple genes, each contributing to different aspects of the coat. Here’s a breakdown using actual genetic results from an Embark test:

  1. Furnishings (RSPO2):

  • Genotype: II

  • Chihuahuas do not have furnishings (the longer facial hair seen in some breeds like Terriers and Schnauzers). This gene is irrelevant to our coat length discussion but is worth noting for overall understanding.

  1. Coat Length (FGF5):

  • Genotype: LhLh

  • This gene is the primary determinant of coat length. The LhLh genotype indicates a long coat. At

  1. Shedding (MC5R):

  • Genotype: CT

  • This gene influences the shedding rate. CT indicates a moderate shedding rate. This trait is independent of coat length and is important for understanding the overall grooming needs of the dog.

  1. Coat Texture (KRT71):

  • Genotype: CC

  • The KRT71 gene affects coat texture. CC genotype usually indicates a straight or slightly wavy coat, typical for Chihuahuas.

  1. Hairlessness (FOXI3):

  • Genotype: N/N

  • This genotype indicates the absence of the hairlessness trait, which is typical for coated breeds like Chihuahuas.

Practical Implications for Breeders

To understand the implications of these genetic traits, let’s focus on the key gene: FGF5 (Coat Length).

  • Smooth-Coated Chihuahua (Sh): The smooth coat is a dominant trait. A Chihuahua with at least one Sh gene (ShSh or ShLh) will have a smooth coat.

  • Long-Coated Chihuahua (LhLh): The long coat is recessive. A Chihuahua needs two copies of the Lh gene to have a long coat.

Scenario: Breeding Two Smooth-Coated Chihuahuas (ShSh or ShLh)

  • If both parents are ShSh (homozygous smooth coat), all offspring will be ShSh, resulting in smooth-coated puppies.

  • If both parents are ShLh (heterozygous smooth coat carrying the long coat gene), the offspring can be:

  • 25% ShSh (smooth coat)

  • 50% ShLh (smooth coat carrying long coat gene)

  • 25% LhLh (long coat)

Quality of Long Coats:

  • The quality of a long coat is not determined solely by the presence of the LhLh genotype. The genes affecting coat texture (KRT71) and shedding (MC5R) also play crucial roles. Therefore, a long-coated puppy from smooth-coated parents (if both carry the long-coated gene) will not necessarily have a poor-quality coat. The genotype CC (KRT71) ensures a good coat texture and CT (MC5R) indicates a moderate shedding rate, both contributing to a healthy, well-maintained coat.

The Importance of Genetic Diversity

Maintaining genetic diversity within the Chihuahua breed is crucial for its overall health and vitality. Limiting breeding practices to a narrow genetic pool can lead to a higher incidence of inherited diseases and reduced fertility. By understanding and leveraging the full range of genetic traits, breeders can ensure a robust gene pool that promotes healthy and resilient dogs.

  • Genetic Diversity and Health: A diverse gene pool reduces the likelihood of genetic disorders. It also enhances the breed's ability to adapt to changing environments and resist common health issues.

  • Breeding Strategies: Incorporating dogs with varied genetic backgrounds can help maintain the breed’s vitality. Responsible breeders should aim to balance desired traits with the need to keep the gene pool wide and healthy.


Breeding two smooth-coated Chihuahuas does not result in poorly coated long-coated offspring. The genetics are clear: coat quality is multifaceted, involving multiple genes beyond just the FGF5 gene. Additionally, maintaining genetic diversity is essential for the health and resilience of the breed. As breeders, it is crucial to understand these genetic intricacies to make informed breeding decisions and maintain the quality and health of our beloved Chihuahuas.

By leveraging genetic testing and a thorough understanding of coat genetics, we can dispel myths and continue to breed Chihuahuas that meet the highest standards. For more insights and detailed discussions on Chihuahua genetics, feel free to reach out or join our breeder community.

Stay informed, breed responsibly, and continue to enhance the beautiful traits of our Chihuahuas!


Featured Posts
Check back soon
Once posts are published, you’ll see them here.
Recent Posts
Search By Tags
Follow Us
  • Facebook Basic Square
  • Twitter Basic Square
  • Google+ Basic Square
bottom of page