ORIGINAL ARTICLE Continuous infusion of propofol or intermittent bolus of tiletamine-zolazepam in feline night monkeys (Aotus infulatus) Rafaela Galante 1 , Jos e A.P.C. Muniz 2 , Paulo H.G. Castro 2 , Dorli S. Amora Jr 1 , Vanessa N. Gris 1 , Elizabeth R. Carvalho 1 & Ricardo G.D′O.C. Vilani 1 1 Veterinary Anesthesia and Analgesia Laboratory, Department of Veterinary Medicine, Federal University of Paran a, Curitiba, Brazil 2 National Primate Center, Evandro Chagas Institute, Ministry of Health, Ananindeua, Brazil Keywords anesthesia – lactate – primate – recovery – total intravenous anesthesia Correspondence Ricardo G.D′O.C. Vilani, Departamento de Medicina Veterin aria, Universidade Federal do Paran a, Rua dos Funcion arios, 1540, Curitiba – Paran a Postal Code 80035-050, Brazil. Tel./fax: 55(41)3350-5623; e-mail: vilani@ufpr.br Institution in which work was performed: National Primate Center, Evandro Chagas Institute, Ministry of Health, Ananindeua – Par a, Brazil. Accepted October 23, 2013. Abstract Background Although commonly used, dissociative anesthesia results in unsatisfactory and long recovery periods. The intravenous anesthetic propo- fol seems to be the most advantageous solution. The objectives of this study were to investigate the required infusion rate of propofol to maintain surgical anesthesia and to compare it to tiletamine-zolazepam in Aotus infulatus. Methods Eight healthy feline night monkeys were anesthetized with propofol (PRO) or tiletamine-zolazepam (TZ) during 60 minutes. Cardiopulmonary parameters, arterial blood gases and lactate and quality and times to recovery were determined. Results Mean infusion rate of propofol was 0.53 Æ 0.10 mg/kg/minute. Car- diopulmonary effects did not show marked differences between groups. Times for hanging, ventral recumbency, and normal ambulation were lower in PRO. Establishment of desirable anesthetic depth was easier, recovery quality was superior, and lactate levels were lower in PRO. Conclusions Compared with tiletamine-zolazepam, minor post-anesthetic adverse events should be expected with propofol anesthesia, as well as faster and better anesthetic recovery. Introduction Feline night monkeys (Aotus infulatus) are small-sized neotropical primates with unique nocturnal habits, which have been extensively used as animal models in biomedical research, such as vaccine research, vision physiology, and susceptibility to viral infections [30]. Captive primates in zoos and research centers, such as Aotus species, often require anesthesia for clinical and surgical procedures. The most common and widely established protocols involve the use of inhaled or disso- ciative agents [33, 46]. Because of the easy intramuscular administration and effective chemical restraint, dissociative drugs such as ketamine and tiletamine have been preferred in world- wide primate facilities. A commercial combination of tiletamine and zolazepam, a benzodiazepine that serves as a muscle relaxant and anticonvulsant, is popular for use in wild animal anesthesia [39]. This association is more potent than ketamine, and its duration of action is longer [26]. However, dissociative anesthesia presents long anesthetic recoveries after extended procedures, mainly when a surgical anesthetic level is required, which is not suitable when handling wild animals that require quick reintegration into the group. Besides the prolonged recovery times, tiletamine-zolazepam used in non-human primates has been associated with hypother- mia, neurological effects, and gastrointestinal complica- tions [17, 36, 40]. Total intravenous anesthesia (TIVA) involves induc- tion and maintenance of the anesthetic plan using only intravenous drugs [9]. Many drugs can be used in TIVA J Med Primatol 43 (2014) 22–30 © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd 22 J Med Primatol doi:10.1111/jmp.12089