CONICET | Buscador de Institutos y Recursos Humanos

Ultrasonographic characterization of domestic cat ovaries during sexual maturation has not been described so far. Thus, the aim of this study was to evaluate bidimensional and Doppler ultrasonographic changes of feline ovaries before and during puberty. Five 3 months old, mixed-bred female cats were exposed to a 14:10 L:D photoperiod. Puberty (Day 1) was diagnosed by the first appearance of more than 80% keratinized vaginal epithelial cells and estrous behavior[1]. Bidimensional ultrasonography, colour-coded and pulsed-wave Doppler evaluation of the ovaries (Toshiba Nemio XG, Tokyo, Japan, 14-MHz linear-array transducer) were carried out on Days -50, -20, -7 and 1. Experimental days were determined retrospectively. Longitudinal and transversal sections of the ovaries were obtained and all anechoic spherical structures were considered to be follicles[2]. In each section, the number of follicles >1 mm was recorded. The maximum diameter (MaxD; mm) of the largest follicle was additionally determined. Peak systolic velocity and end diastolic velocity of intraovarian arteries were measured to automatically calculate the resistance index (RI)[3]. Repeated measures ANOVA followed by Tukey test was carried out to evaluate the effect of time on the bidimensional and Doppler ultrasonographic parameters (SPSS 18.0; SPSS, Chicago, IL, USA). The level of significance was set at 0.05.In all bidimensional sonographic images the ovaries appeared ovoid and hypoechoic compared to the surrounding tissues. The mean ovarian longitudinal diameter increased gradually throughout the study from 7.8 to 11.2 mm (P0.05). In all five animals, multiple submillimetric anechoic spherical structures were detected at Days -50 and -20, and in four cats also at the later prepubertal stages. On Days -20, -7 and 1, the mean number of follicles was 1.2±0.96, 2.2±1.1 and 4.8±1.8, respectively (P0.1). The RI of the intraovarian arteries declined throughout the study period (P