Histological changes in the testicle of a calico cat

Abstract A cat that presents orange and black colours (tortoiseshell), or all three colours (calico), is expected to be female since orange and black are colours related to the X chromosome, and white to the autosomal chromosomes. This study reported the case of an entire male calico cat. During the physical examination, the penis exposure allowed visualisation of the spicules typically found in this species. No changes were found in the testicular ultrasound. After orchiectomy, the testicles were submitted to histopathological analysis. Histological examinations revealed seminiferous tubules that only presented Sertoli cells, with an absence of germ cells and hyperplasia in Leydig cells within the interstitial tissue. Both epididymides contained no sperm, allowing us to infer that a calico pattern can be present in males and is associated with gonadal changes that impact male fertility.