Objective To provide appropriate evaluation method and accurate data to support the study of pediatric nervous system drugs, the functional observation battery (FOB) was used to evaluate the effects of different nervous system drugs on juvenile Beagle dogs. Methods Juvenile Beagles were randomly assigned to negative control, nikethamide ( 25 mg / kg), caffeine ( 30 mg / kg), and phenobarbital groups ( 12 mg / kg). All groups received a single administration; the negative control group was administered 0. 9% sodium chloride by injection,while the other groups received their respective drugs. FOB assessments were conducted at baseline (pre-dose) and 1, 2, and 3 h post-dose. Results Compared with the negative control group, the nikethamide group exhibited increased respiratory rate and enhanced facial sensory examination scores following drug intervention (P<0. 05), with vomiting observed in 1 / 6 animals. The caffeine group showed increased respiratory rate, elevated responses to visual and auditory stimuli, and accelerated proprioceptive positioning (P<0. 05), along with abnormal hypoglossal reflex in1 / 6 animals and stereotyped behavior in 3 / 6 ( P<0. 05). The phenobarbital group demonstrated decreased neck muscle and limb tone as well as slowed proprioceptive positioning (P<0. 05), with reduced extensor postural thrust,triceps, and patellar reflexes (P<0. 05). Conclusions In this study, the FOB method appears to be suitable for evaluating pediatric nervous system drug toxicity in juvenile Beagles. It effectively identified specific toxic manifestations induced by commonly used clinical nervous system drugs, such as nikethamide, caffeine, and phenobarbital.