Effect of Long term melatonin administration in pre and pospubertal domestic cats (Felis catus)

M FAYA; A RISSO; A CARRANZA; Y PAGANELLI; T PONCHÓN; M CALABOZO; BAROVERO; C GOBELLO

Jornada; Segundas Jornadas Internacionales del Instituto de Investigación y Tecnología en Reproducción Animal; 2010

The aim of this study was to assess the efficacy and safety of melatonin long term administration (either as an implant or an oral presentation) on domestic cat interestrousintervals. Additionally, the effect of melatonin implants on puberty postponement has been studied. Two randomized controlled trials were conducted. In the first one, 68 interestrous intervals of 28 postpubertal queens were studied and in the second 29 prepubertal female cats were used. During non-ovulatory interestrous intervals the postpubertal cats were assigned to: melatonin implant 18 mg/cat sc (n = 17; MEI), melatonin tablets 4 mg/cat q 24 hours po (n=12; MEO) until estrus onset or control (n = 12; CTL). The prepubertal females were randomly assigned to: melatonin 18 mg/cat sc implants at either 1.9±0.3 (MEI-A; n = 10) or 1.5±0.3 kg (MEI-B n = 10) body weight or control (CTL, n = 9). Interestrous intervals in the postpubertal MEI, MEO and CTL groups were 63.8 ± 5.4, 63.0 ± 5.3 and 19.2± 1.4 days (p<0.05), respectively. Treatment onset – first estrous cycle interval in the same groups were 51.0 ± 4.7, 50.0 ± 6.1 and 12.6 ± 1.1days (p<0.05). In the second experiment, neither age (MEI-A [232.9±11.5 days] vs. MEI-B [208.6±13.0 days] vs. CTL [190.1±22.4 days]; p > 0.1) nor body weight (p > 0.1) at puberty differed among groups. None of the cats of both studies presented side effects. It was concluded that long term melatonin treatment shortly prolongs interestrus but does not postpone puberty in domestic cats.