Introduction

Responsible Chihuahua breeding goes beyond aesthetics: it involves planning breedings with the long-term health of the puppies in mind. Two key tools in this process are COI (coefficient of inbreeding) and genetic/DNA testing.

What is the IOC and why does it matter?

The COI measures the degree of inbreeding of a puppy based on its ancestors. A low COI indicates:

• Lower risk associated with inbreeding.

• A more diverse genetic base.

• Better long-term health prospects.

At Heirs of Feal, many published puppies show very low COIs (e.g. 0.85% or 0.04%), reflecting careful planning of crosses.

DNA and parentage testing

DNA tests allow:

• Confirm the parentage between parents and puppies.eds2025

• Register correctly in the LOE with complete genealogy.

• Offer greater transparency to the future owner.

In our litters, puppies are presented with sire, dam details and DNA availability where applicable.

Breed disease testing

The Chihuahua, as a breed, may be predisposed to certain pathologies (patella dislocation, eye problems, heart problems, etc.). Specific tests help:

• Detect carriers of hereditary diseases.

• Avoid risky crossings.

• Inform the buyer about the health status of the puppy.

At Heirs of Feal, puppy sheets include information on COI, DNA, and availability of breed disease testing when available.

Conclusion

Working with controlled COI, DNA and health testing is not a luxury, it is part of responsible breeding. If you are looking for a healthy and well-planned Chihuahua, these are the criteria you should take into account.

Do you want to know how we apply COI, DNA and health tests on our litters? Contact us and we will send you detailed information about our puppies.