Phenobarbitone concentrations in the hair, saliva and plasma of eight epileptic dogs.

Samples of plasma, saliva and hair were collected from eight dogs receiving phenobarbitone for idiopathic epilepsy. The concentrations of phenobarbitone in hair and plasma were correlated with the daily dose rate, and the concentrations in hair were also correlated with the concentration in plasma, the dose rate of the drug over the preceding six months and the ratio of the six-month dose to body surface area. The concentration of phenobarbitone in saliva was not correlated with either the concentration in plasma or the dose rate of the drug.