What is Fetal Sex Determination?
Fetal Sex Determination (FSD) is the process of identifying the sex of an unborn foal while it is still in the mare's uterus. This critical information allows breeders to make informed decisions about their breeding program, marketing strategy, and resource allocation.
While there are several methods available for determining fetal sex in horses, ultrasound examination is the most common and practical approach. However, the accuracy of ultrasound-based FSD varies significantly depending on the skill and experience of the veterinarian performing the procedure.
Dr. Kevin J. Doyle has developed a proprietary technique that achieves results beyond all doubt in fetal sex determination through ultrasound. This unparalleled level of accuracy has made KJD Veterinary the trusted choice for elite breeding operations worldwide.
The Science Behind FSD
Fetal sex determination in horses is based on the identification of specific anatomical structures that differentiate male from female fetuses. The genital tubercle, which develops into either male or female genitalia, is the primary structure examined during ultrasound.
The position of this tubercle relative to other anatomical landmarks changes as the fetus develops, making the timing of the examination critical for accurate determination.
Comparing FSD Methods
Understanding the differences between available methods for equine fetal sex determination
Ultrasound (Standard)
Standard ultrasound examination is the most common method used by veterinarians. It involves visualizing the genital tubercle and other anatomical structures to determine fetal sex.
Non-invasive procedure
Can be performed during routine pregnancy checks
Accuracy highly dependent on veterinarian skill and timing
PCR Testing
PCR testing involves analyzing DNA from fetal cells collected from the mare's bloodstream or amniotic fluid to determine the presence of Y-chromosome markers.
High accuracy rate
More invasive procedure
Longer turnaround time for results
Higher cost
KJD Ultrasound Technique
Dr. Doyle's proprietary ultrasound technique combines specialized equipment, precise timing, and expert interpretation to achieve results beyond all doubt in fetal sex determination.
Beyond all doubt accuracy, verified by thousands of cases
Non-invasive procedure
Immediate results
Backed by Logan's Insurance guarantee
The KJD Advantage
What sets our fetal sex determination services apart from all others
Beyond All Doubt Guarantee
Our determinations are backed by our Beyond All Doubt guarantee. Our service, Beyond All Doubt, provides the highest level of scientific and medical certainty achievable.
Optimal Timing
We perform FSD during our extended service window (55-250 days of gestation) when fetal sex characteristics are most clearly visible, ensuring the highest possible accuracy.
Expert Verification
Every determination made by our certified veterinarians is personally reviewed and verified by Dr. Doyle himself, ensuring consistent quality and accuracy.
Official Certification
Each determination comes with an official KJD Veterinary certificate, providing documentation that can be used for marketing, sales, and insurance purposes.