Pulse Doppler ultrasound as a tool for the diagnosis of chronic testicular dysfunction in stallions.
Authors: Ortiz-Rodriguez Jose M, Anel-Lopez Luis, Martín-Muñoz Patricia, Álvarez Mercedes, Gaitskell-Phillips Gemma, Anel Luis, Rodríguez-Medina Pedro, Peña Fernando J, Ortega Ferrusola Cristina
Journal: PloS one
Summary
# Editorial Summary: Pulse Doppler Ultrasound for Diagnosing Testicular Dysfunction in Stallions Vascular compromise of testicular tissue significantly impairs spermatogenesis and ejaculate quality, yet timely identification of dysfunction remains challenging in breeding soundness evaluations. Ortiz-Rodriguez and colleagues compared Doppler ultrasonographic parameters across three testicular arterial locations (supratesticular, capsular, and intratesticular) in seven healthy and three subfertile stallions, correlating blood flow measurements with sperm integrity, mitochondrial activity, and DNA fragmentation assessed via flow cytometry across 48 hours of cooled storage. The capsular artery proved most diagnostically valuable, with fertile stallions characterised by elevated end-diastolic velocity, time-averaged maximum velocity, and total arterial blood flow (reflecting robust perfusion), whilst subfertile animals demonstrated elevated resistive and pulsatility indices indicating vascular resistance; ROC curve analysis identified peak systolic velocity, end-diastolic velocity, capsular artery diameter, and tissue perfusion parameters as the strongest predictors of semen quality with clinically applicable cut-off values. For practitioners managing breeding stallions, this research establishes Doppler ultrasonography as a non-invasive, repeatable diagnostic technique capable of identifying testicular vascular insufficiency before significant fertility loss occurs—potentially circumventing the need for more invasive diagnostic procedures whilst enabling earlier intervention in cases of declining semen quality.
Read the full abstract on PubMed
Practical Takeaways
- •Doppler ultrasound of the capsular artery offers a non-invasive diagnostic alternative to traditional invasive procedures for identifying testicular dysfunction in breeding stallions
- •Measuring blood flow parameters (particularly EDV, TAMV, and TABF) and vascular resistance indices (PI, RI) can help predict sperm quality and breeding potential before investing in breeding soundness exams
- •Establishing individual stallion Doppler baseline values and monitoring changes over time may enable early detection of testicular pathology and allow timely intervention to preserve fertility
Key Findings
- •Capsular artery Doppler parameters showed strongest correlation with sperm quality markers assessed by flow cytometry
- •Fertile stallions characterized by high end diastolic velocity (EDV), time average maximum velocity (TAMV), and total arterial blood flow (TABF); subfertile stallions showed high pulsatility index (PI) and resistive index (RI)
- •Doppler velocities (PSV, EDV, TAMV), capsular artery diameter, and TABF parameters were best predictors of sperm quality with established cutoff values via ROC analysis
- •Spectral Doppler ultrasound showed significant differences in all Doppler parameters between fertile and subfertile stallions (p ≤ 0.05)