In cats, assessment of the testicular function is mainly based on sperm evaluation. Whatever the technique used, the volume of collected sperm is often small, which may lead to technical difficulties to achieve the semen evaluation in routine practice. Fine‐needle aspiration (FNA) biopsy of the testicular parenchyma is one of the other methods used to assess testicular function. The aim of this study was to explore the relevance of FNA in the assessment of testicular cells in sexually mature cats. Eighteen cats over one year of age were recruited among animals presented for surgical neutering. Semen was collected by electroejaculation before it was evaluated. FNA biopsies of the testicles were taken using a 21‐gauge needle. After castration, histological analysis of the testes was performed. Semen evaluation and histological analysis showed no anomalies, which confirmed normal spermatogenesis in all the cats and allowed a proper interpretation of the cytological findings. The cells identified through cytological examination were spermatogonia (1.99 ± 0.17%), primary spermatocytes (10.49 ± 0.74%), round spermatids (34.80 ± 1.57%), elongated spermatids (23.59 ± 2.02%), spermatozoa (21.56 ± 1.86%), Sertoli cells (7.53 ± 1.23%) and Leydig cells (0.04 ± 0.03%). However, spermatocytes II were not identified. This is due to the low proportions of these cells, related to their very short lifespan. Likewise, the very low number of Leydig cells observed is probably due to the damage caused during the aspiration stage. This study showed that fine‐needle aspiration is an efficient method to describe cytologically normal testicular populations, a cornerstone for future research aimed to study abnormal spermatogenesis and to correlate it to cytological proportion of germ cells.

中文翻译：

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具有正常精子发生能力的性成熟猫睾丸细胞群的细胞学描述

在猫中，睾丸功能的评估主要基于精子评估。无论使用哪种技术，精子的采集量通常都很小，这可能导致在常规实践中难以实现精液评估的技术难题。睾丸实质的细针穿刺活检是用于评估睾丸功能的其他方法之一。这项研究的目的是探讨FNA在性成熟猫的睾丸细胞评估中的相关性。在提出用于手术绝育的动物中招募了十八岁以上的猫。通过电射精收集精液，然后对其进行评估。使用21号针头对睾丸进行FNA活检。去势后，进行睾丸的组织学分析。精液评估和组织学分析未发现异常，这证实了所有猫的正常生精，并能正确解释细胞学发现。通过细胞学检查发现的细胞是精原细胞（1.99±0.17％），原代精母细胞（10.49±0.74％），圆形精子（34.80±1.57％），细长精子（23.59±2.02％），精子（21.56±1.86％）， Sertoli细胞（7.53±1.23％）和Leydig细胞（0.04±0.03％）。但是，未鉴定出精细胞II。这是由于这些细胞的比例很低，与它们的寿命很短有关。同样，观察到的Leydig细胞数量非常少，可能是由于在抽吸阶段引起的损伤。这项研究表明，细针穿刺术是描述细胞学正常睾丸种群的有效方法，