Monitoring of vital signs of animals is essential during anesthesia procedures and surgery being the heart rate (HR) one of the parameters evaluated and it is necessary to use reliable methods. Aiming to evaluate the accuracy of two methods of measuring HR in dogs, there was a comparative study of two devices used for this purpose, these being an oscillometric measuring equipment (Petmap®) and a heart monitor multiparameter (Cardiovet). 71 healthy young bitches were evaluated under inhalation anesthesia during surgery elective ovariohysterectomy with isoflurane. From the beginning of the surgery, which lasted 30 minutes on average, the values of heart rate were measured by both devices every 10 minutes, for a total of three measurements per animal. We calculated the average of the three measured values and used the average for descriptive and evaluation by the Student t test statistic. The results for the oscillometric machine and heart monitor were respectively 106.35 and 108.56 ± 16:15 ± 20.28 bpm, not statistically different (p> 0.05). This shows the similarity of the accuracy of the two devices in measuring the heart rate of dogs, indicating that the choice of equipment can be charged to the veterinarian, according to your need in the medical and surgical clinic, since the oscillometric device measures well as blood pressure and heart monitor additionally provides electrocardiographic data.