Radiographic and Biochemical Evaluations of Postnatal Development of Bones of the Forelimb in Nigerian Indigenous Dogs.

Bone is a hard and resilient tissue structure that provides mechanical support for the body of an organism. This study was aimed to evaluate the radiographical and biochemical changes during postnatal bone development of forelimbs in Nigerian indigenous puppies from 2-week-old to 24-week-old. Six (6) Nigerian indigenous puppies were chemically restrained using chlorpromazine at 2 mg/kg I.M. and positioned using ropes and sandbags for mediolateral and craniocaudal views of bones of the forelimbs. At 2-week-old, radiographic evaluation of bones of the forelimbs were undertaken and continued bi-weekly up to 24-week-old. Serum samples were analysed from 4-week-old to 24-week-old at four weeks’ interval for mineral (electrolytes) using colometric method for calcium and phosphorus and flame photometry method for sodium and potassium. At 2-week-old, there was an ill-defined radiopaque secondary ossification centre at the proximal epiphysis and a small ovoid radiopaque structure at the distal epiphysis of the humerus. There was not any sign of secondary ossification centre at proximal and distal epiphyses of both radius and ulna. There was the presence of a small radiopaque (ill-defined) accessory carpal. 1st to 5th metacarpals were present together with the proximal, middle and distal phalanges of all digits except the 1st digit that has proximal and distal phalanges. From 20-week-old, fully developed carpals and bony structures were observed through 24-week-old where the commencement of fusion of apophyses of olecranon (proximal epiphysis of ulna) at the centre and acrophyses of metacarpals and phalanges. The mean values (mean ± SEM) from serum biochemistry of calcium, phosphate, sodium and potassium in mmol/L from this study were within the normal limits throughout the study. Conclusively, the complementary information from calcium, phosphate, sodium and potassium in this study showed that these elements are within the normal limit that suggests normal bone development during the study period, which stressed the importance of the knowledge on serial changes of bone development which could be useful in clinical practice.