The prolonged use of dopamine replacement therapy (DRT) in Parkinson’s disease (PD) is associated with the onset of non-motor complications, including iatrogenic psychiatric-like disturbances. However, the preclinical investigation of the latter is limited, due to the lack of reliable animal models. In this regard, we developed a new model consisting in the evaluation of 50-kHz ultrasonic vocalizations (USVs), a behavioral marker of positive affect, in rats unilaterally lesioned with 6-hydroxydopamine (6-OHDA) in the medial forebrain bundle and treated with either apomorphine or L-DOPA, two drugs used in the DRT of PD. To further validate our model, in the present study we evaluated how acute and repeated administration of apomorphine/L-DOPA at doses that elicited 50-kHz USV emissions modified the levels of Zif-268 (a marker of neuronal activation) in the nucleus accumbens (NAc), striatum and medial prefrontal cortex (mPFC), which are all brain regions whose dysfunction underlies the manifestation of iatrogenic psychiatric-like disturbances in PD patients. Hemiparkinsonian rats treated with either apomorphine or L-DOPA markedly vocalized during acute/repeated pharmacological treatment and displayed increased levels of Zif-268 in the NAc and striatum but not mPFC, indicating that subcortical and cortical areas differently regulate the vocal expression of positive affect in hemiparkinsonian rats treated with dopaminergic drugs used in the DRT of PD. These results suggest that measuring the emission of 50-kHz USVs may be relevant to further characterizing at the preclinical level the effects that drugs used in the DRT of PD elicit on the emotional state.