Cytological identification and quantification of testicular cell types using fine needle aspiration in horses.
Authors: Leme D P, Papa F O
Journal: Equine veterinary journal
Summary
# Editorial Summary: Testicular Cytology via Fine Needle Aspiration in Stallions Fine needle aspiration cytology (FNAC) offers a minimally invasive method for directly assessing spermatogenic activity in stallion testicles, potentially streamlining the diagnostic investigation of subfertility or breeding soundness concerns. Leme and Papa evaluated testicular samples from 15 stallions aged 3–11 years using FNAC, quantifying the proportions of key cell populations including spermatogonia (1.6%), primary and secondary spermatocytes (3.4% and 0.8% respectively), early and late spermatids (25.5% and 37.0%), mature spermatozoa (spermatic index: 31.5%), and Sertoli cells (Sertoli cell index: 20.9%). The technique proved reliable for cell identification with minimal reported discomfort, establishing baseline cytological profiles that practitioners and veterinarians can reference when evaluating testicular health. For equine practitioners working with breeding stallions, FNAC represents a non-surgical alternative to tissue biopsy for gathering objective data on spermatogenic progression and germ cell populations, potentially helping distinguish between obstructive versus secretory infertility and guiding management or treatment decisions without significant risk to the animal.
Read the full abstract on PubMed
Practical Takeaways
- •FNAC offers a practical, minimally invasive method to assess testicular cytology and spermatogenesis in subfertile stallions without causing observable tissue damage
- •Establishing reference ranges for spermatogenic and Sertoli cell percentages via this technique may help practitioners objectively quantify testicular function during fertility evaluations
- •This diagnostic approach could improve clinical decision-making in breeding soundness examinations and infertility investigations
Key Findings
- •Fine needle aspiration cytology successfully identified and quantified spermatogenic cell types in stallion testes with early spermatids (25.5% ± 9.5) and late spermatids (37.0% ± 9.3) being the predominant cell types
- •Spermatic index averaged 31.5% ± 8.5 and Sertoli cell index averaged 20.9% ± 17.0 in the 15 stallions evaluated
- •Cell type identification was relatively easy and no immediate adverse effects from aspiration were observed in any animal
- •FNAC shows promise as a clinical diagnostic tool to assist in evaluation of male equine infertility