The purpose of the present study was to test whether the addition of cisatracurium in combination with propofol and sevoflurane would result in a change in doses of used anesthetic drugs. Ten dogs (Group A) undergoing elective unilateral mastectomy surgery were included in the study. To induce and maintain anesthesia, subjects received propofol and sevoflurane at varying doses; analgesia was performed with remifentanil. After three months, the same subjects (Group B) underwent contralateral mastectomy and received the same anesthetic protocol with the addition of cisatracurium at a dosage of 0.2 mg/kg. The following parameters were monitored during anesthesia: heart rate, systolic blood pressure, end-tidal CO, oxygen saturation, halogenate requirement, and rectal temperature at baseline (T), induction (T), 5 (T), 10 (T), 15 (T), 20 (T), 25 (T), 30 (T), and 35 (T) time points. In Group A, halogenate requirement was reduced at all the time points other than T1 ( < 0.001); in Group B, the percentage of halogenate requirement was already reduced at T and remained constant during the experimental period, showing no significant intragroup differences. The dose requirements of sevoflurane and propofol varied significantly between the two groups, with significantly lower dosages in the Group B (the cisatracurium-treated group). Moreover, patients treated with cisatracurium showed a stable anesthetic plan. The nondepolarizing-muscle-relaxant cisatracurium besylate could be considered a useful adjunct to anesthetic protocols.