In the current experimental study, two different instruments were compared for prophylactic hemostasis during a 3-port technique of laparoscopic ovariohysterectomy (OVH) in bitches. Moreover, the need for port enlargement for specimen retrieval using 5mm or 10mm trocartes, technical difficulties and complications were assessed. Ultrasonic energy and a vascular sealing system were tested. Duration of surgery, patient weight and diameter of the uterine arteries and veins were compared among the groups. Fifteen dogs randomly divided into three groups (GI, GII, GIII) were submitted to ovariohysterectomy with hemostasis from the use of ultrasonic scalpel or vascular sealing equipment. In GI and GII the LigaSure ™ impedance-controlled bipolar vessel-sealing device was used, differing in the size of trocartes used between groups, and in GIII Autosonix ™ was used. Patients' weight, duration of surgery, technical difficulties and complications were compared among the groups. Statistical analysis showed no difference between the data analyzed among the groups. In conclusion, both methods of hemostasis were effective for 3-port total laparoscopic ovariohysterectomy in bitches. However, 5mm trocartes were not adequate for retrieval of the uterus and ovaries without need for enlargement of the port incision.Keywords: laparoscopy, canines, coagulation systems, spay, surgery RESUMO No presente experimento, foram comparados dois diferentes equipamentos, um com emprego de energia ultrassônica, e outro utilizando sistema de selamento vascular, como única forma de hemostasia em ovário-histerectomias laparoscópicas com três portais em cadelas. Ademais, a necessidade de ampliação da incisão do portal de 5mm ou de 10mm para a remoção dos espécimes ressecados, dificuldades técnicas e complicações foram avaliadas. Quinze cadelas aleatoriamente distribuídas em três grupos (GI, GII, GIII) foram submetidas à ovário-histerectomia com hemostasia a partir da utilização de bisturi