ABSTRACT. Lima D.A.S.D., Souza A.P., Borges O.M.M., Santana V.L., Araújo A.L., Figueirêdo L.C.M., Nóbrega Neto P.I. & Lima W.C. [Comparative study of the association of Ketamine to Dexmedetomidine, Medetomidine or Xylazine in rabbits.] Estudo comparativo da associação de Cetamina à Dexmedetomidina, Medetomidina ou Xilazina em coelhos. Revista Brasileira de Medicina Veterinária 36(1):35-41, 2014. Programa de Pós-Graduação em Medicina Veterinária, Centro de Saúde e Tecnologia Rural, Universidade Federal de Campina Grande, Av. Universitária, s/n, Patos, PB 58708-110, Brasil. E-mail: firstname.lastname@example.org There are a variety of different anesthetic techniques that aim to overcome the various problems of anesthesia in rabbits, such as handling stress and apnea during induction with inhalational anesthetic agents, reducing the risks of the procedure. The objective of this study was to compare the anesthetic effects promoted by ketamine associated/mixed with three different agonists α2 -adrenergics in rabbits. Were used 6 healthy animals, (SRD) mixed breed, weighing 2.42+0.36 kg, submerged to treatments called GCX, GCD and GCM. The fixed-dose ketamine (15 mg/kg) combined with xylazine (10 mg/kg) was administered intramuscularly in the GCX, the dexmedetomidine (0.05 mg/ kg) in GCD and medetomidine (0.25 mg/kg) in the GCM. Were evaluated the heart rate (HR), respiratory rate (ƒ), rectal temperature (RT), oxyhemoglobin saturation (SpO2 ), mean arterial pressure (MAP), glucose (GLI), variables electrocardiography (Pms, PmV, PRms, QRSms, RmV, QTms, RRms), latency, able anesthetic and recovery period. The records of the variables were initiated before drug administration (basal) and every 5 minutes after taking them for 50 minutes. Data were subjected to ANOVA followed by the Tukey test (P<0.05), for the clinical variables, and the “t” test of Student (P<0.05) for the other variables. More stable HR and MAP, respectively were obtained in the GCD and the GCM. There was a reduction of the average of ƒ and hyperglycemia in all groups. The PR in GCX had high averages from M5. We conclude that the effects were similar in both groups and without significant changes in the physiology of rabbits. It is worth mentioning a better cardiovascular stability associated with the use of dexmedetomidine.