Although purebred cat breeding is growing in popularity in European countries, most research and publications concern dog reproduction. Infertility in queens has been poorly studied. It may not come as a surprise as common domestic shorthair cats are well known for their excellent fertility. However, even in the latter, the infertility rate is around 20%. Only recently, published articles have analyzed the reproductive performances in different breeds, for example in UK, Sweden, France and Italy, and found similar figures. In cats, infertility may arise from many factors such as mismating, prolonged anestrus or silent heats, hormonal, nutritional, genetical or chromosomal causes. Also, infectious diseases, probably frequent in breeding facilities, include pathological agents that are well recognized as having a negative effect on pregnancy or other pathogens for which the involvement in fertility problems is unclear. However, analyzing the literature, it appears that the most prevalent causes of infertility in pedigree cats may well be, in females, uterine pathology (sub-clinical endometritis, cystic endometrial hyperplasia, or mucometra), and in males, teratospermia, which may be “permanent” and linked to reduced heterozygosity or “transient” in tomcats that present normal quantitative spermatogenic parameters. The influence of the breed is unknown. There is an urgent need to study the origin of infertility in purebred cats in order to improve the diagnosis and to develop treatments that may restore normal fertility in subfertile or infertile animals.

中文翻译：

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纯种猫不育——潜在原因回顾

尽管纯种猫育种在欧洲国家越来越受欢迎，但大多数研究和出版物都关注狗的繁殖。蜂后的不孕症研究很少。这可能不足为奇，因为普通的家养短毛猫以其出色的生育能力而闻名。然而，即使是后者，不孕率也在20%左右。直到最近，发表的文章分析了不同品种的繁殖性能，例如在英国、瑞典、法国和意大利，并发现了相似的数字。在猫中，不孕症可能由许多因素引起，例如错配、长时间的无情期或无声发情、激素、营养、遗传或染色体原因。此外，传染病，可能在繁殖设施中很常见，包括公认对怀孕或其他与生育问题有关的病原体有负面影响的病原体。然而，通过对文献进行分析，似乎导致纯种猫不孕的最常见原因很可能是雌性的子宫病变（亚临床子宫内膜炎、囊性子宫内膜增生或粘液），以及雄性的畸形精子症，这可能是“永久性”并与呈现正常定量生精参数的雄猫的杂合性降低或“暂时性”相关。品种的影响是未知的。迫切需要研究纯种猫不育的起源，以改进诊断并开发可能恢复不育或不育动物正常生育能力的治疗方法。看来，纯种猫不孕的最常见原因很可能是，在雌性中，子宫病理学（亚临床子宫内膜炎、囊性子宫内膜增生或粘液），而在雄性中，畸精症可能是“永久性的”并与以下因素有关在呈现正常定量生精参数的雄猫中降低杂合性或“暂时性”。品种的影响是未知的。迫切需要研究纯种猫不育的起源，以改进诊断并开发可能恢复不育或不育动物正常生育能力的治疗方法。看来，纯种猫不孕的最常见原因很可能是，在雌性中，子宫病理学（亚临床子宫内膜炎、囊性子宫内膜增生或粘液），而在雄性中，畸精症可能是“永久性的”并与以下因素有关在呈现正常定量生精参数的雄猫中降低杂合性或“暂时性”。品种的影响是未知的。迫切需要研究纯种猫不育的起源，以改进诊断并开发可能恢复不育或不育动物正常生育能力的治疗方法。这可能是“永久性的”，并且与呈现正常定量生精参数的雄猫的杂合性降低或“暂时性”有关。品种的影响是未知的。迫切需要研究纯种猫不育的起源，以改进诊断并开发可能恢复不育或不育动物正常生育能力的治疗方法。这可能是“永久性的”，并且与呈现正常定量生精参数的雄猫的杂合性降低或“暂时性”有关。品种的影响是未知的。迫切需要研究纯种猫不育的起源，以改进诊断并开发可能恢复不育或不育动物正常生育能力的治疗方法。