Fecal estradiol-17β and testosterone in prepubertal domestic cats

CARRANZA A; FAYA M; GARCÍA P; DE LA SOTA P; GOBELLO C

Toulouse

Congreso; EVSSAR Congres 2013; 2013

EVSSAR

Introduction and aim. Most newborn mammals present an elevated production of sexual hormones which will subsequently decline to slowly achieve typical prepubertal values until sexual maturity (1,3). Interference with normal pituitary-gonadal function during this time window impacts adversely on the genital tract development and reproductive performance. Present knowledge about the prepubertal sexual steroids and the critical time window of vulnerability is null in domestic cats (4). The aim of this study was to describe the time course of prepubertal sexual steroids in domestic cats (Felis catus domesticus). Materials and methods. Fourteen newborn crossbred kittens were reared under our colony conditions and followed up by physical examination, behaviour observation and faecal sample collection for measurement of oestradiol 17-β (E2) concentrations in females and concentrations of testosterone (T) in males until puberty (Elecsys, Roche Diagnostics, Mannheim, Germany; 2). Faecal steroids were extracted and hormones determined by electrochemiluminescence immunoassays. Faecal T and E2 concentrations were analyzed by repeated measures ANOVA and 2 consecutive time windows (TW) were compared for both male (postnatal weeks 1 to 4 vs. 5 to 14) and females (postnatal weeks 1 to 5 vs. 6 to 13). Results. Puberty was achieved 14.3±0.3 and 13.3±0.4 weeks after birth in male and female cats, respectively. In both genders, during TW-1 faecal steroids concentrations were similar or even higher to that previously described for mature cats. Faecal T (P < 0.01) and E2 (P < 0.01) varied throughout the weeks. Differences were found when hormonal concentrations of TW-1 were compared to those of TW-2 both for male (61.4±7.9 vs. 16.9±2.2 ng/g; P