19-nortestosterone detection in canine plasma after intramuscular administration of 19-nortestosterone phenylpropionate.

A proven radioimmunoassay method for monitoring 19-nortestosterone (nandrolone) was combined with high pressure chromatographic fractionation on a microparticulate silica gel using 1,2 dichloroethane/ethanol as the mobile phase. Plasma levels of 19-nortestosterone were monitored for seven days after intramuscular administration of nandrolone phenylpropionate (1.5 mg kg-1) to a beagle and a German shepherd dog. After 24 hours the plasma level in both bitches was 20 ng ml-1 and reverted to baseline after the fourth day after injection. Nandrolone was shown to be the only detectable exogenous steroid present in the post injection plasmas and could be distinguished from any potential cross reacting metabolites. The radioimmunoassay method can therefore be applied to the evaluation of nandrolone in the management of canine chronic renal disease in the bitch.