The age at puberty of the Nigeria Local Dogs (NLD) in Ibadan was studied by monitoring the changes in their weekly live body weight, semen parameters, testicular, epididymal biometry and testosterone profile. The puppies were selected randomly from different healthy litters at different regions of Ibadan metropolis. These dogs were divided into four age groups consisting of 3 animals in each group, namely, group-A (12 weeks), group-B (16 weeks), group-C (20 weeks) and group-D (24 weeks). Weekly live body weights of the puppies were obtained from 7 weeks to 24 weeks of age. Blood samples were collected at 12, 16, 20 and 24 weeks into EDTA bottles and the plasma decanted were assayed for testosterone. The puppies were castrated at 12, 16, 20 and 24 weeks. Semen was collected from the caudal epididymis and evaluated. The result showed a positive linear relationship (P < 0.05) between the age and body weight of the dogs with R (correlation coefficient) = 0.980. The right testes had higher values of the testicular and epididymal parameters compared to the left testes. There was a linear relationship among weight of dog, testicular weight and corresponding percentage. There were fluctuations in the levels of testosterone during this study and a significant difference in the results of testosterone before and after castration (P < 0.05). It was therefore concluded that Nigerian local dogs do not have spermatozoa present in their semen and have very low serum testosterone level before 24 weeks of age, therefore puberty in the Nigerian local dog does not occur before 24 weeks of age and results of this study can be used as a baseline data in the further study of the classification and characterization of the NLD.
Key words: Age, Epididymis, Nigerian Local dog, Testes, Testosterone.
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