Division of Comparative Medicine


The Division of Comparative Medicine is responsible for all aspects of animal care contributing to the welfare of the Oregon National Primate Research Center's animal colonies. This multi- faceted program includes daily husbandry, the provision of veterinary medical care, and the development and implementation of the Nonhuman Primate Behavioral Management Plan, which addresses the psychological needs of our monkeys. The Division also provides research support services including collaboration with investigators about how to best address the welfare needs of their animal models. The Division consists of eight functional units: 

  • Administration
  • Behavioral Services Unit
  • Clinical Medicine Unit
  • Education and Training Unit
  • Operations Unit
  • Pathology Services Unit
  • Resources and Logistics Unit
  • Surgical Services Unit

The Division is staffed by approximately 160 dedicated individuals, including 15 Faculty veterinarians, three PhD level nonhuman primate behaviorists, two veterinary residents, in addition to veterinary, behavioral and animal care technicians and administrative staff.

The Chief of the Division of Comparative Medicine (DCM) is Dr. Gregory Timmel, who also serves as the Associate Director and Attending Veterinarian for the Oregon National Primate Research Center.  As Division Chief, Dr. Timmel oversees a team of veterinarians, Ph.D. scientists, and experienced animal care managers, who collectively provide experienced and skilled leadership for each of the eight functional units within the Division. Together, the DCM leadership team delivers effective and efficient management for the animal care program and provides an experienced cadre of technical, husbandry and behavioral personnel for research support services. Dr. Lauren Drew Martin serves as the Assistant Chief, DCM, and serves as Interim Chief, DCM, and Attending Veterinarian in Dr. Timmel's absence.

Grooming of an adult Rhesus Macaque

The Behavioral Services Unit (BSU) at the Oregon National Primate Research Center (ONPRC) is devoted to the psychological well-being of our nonhuman primates (NHPs).  The primary goal of the unit is to provide conditions that afford the NHPs opportunities to express species-typical behaviors (such as grooming and foraging), thereby improving their welfare.  The BSU collaborates with husbandry, veterinary and scientific staff to implement the ONPRC Nonhuman Primate Behavioral Management Plan, which provides for the social and behavioral needs of our monkeys.

Social housing

NHPs are social animals that form complex relationships in their natural habitats.  Therefore, providing them with social opportunities is one of the best ways to promote their psychological well-being.  The vast majority of the NHP population at ONPRC lives in large outdoor or indoor/outdoor groups; the remaining animals primarily live indoors in small groups or paired housing.  Whenever possible, we pair house indoor maintained NHPs; i.e., keep two monkeys in two cages to which both members have complete access.  Providing and maintaining social housing for our NHPs is a top priority of the BSU.

Environmental enrichment

Environmental enrichment refers to the objects and stimuli we provide animals in an effort to promote optimum psychological wellbeing. Enrichment strives to functionally simulate, in captivity, the most relevant aspects of the species’ natural environment and increase opportunities for expression of species-typical behaviors such as foraging and exploration. Monkeys are given enrichment items, such as manipulanda (toys), swings, climbing structures and other items to increase behavioral diversity. These objects are rotated on a regular basis to keep them novel. Our monkeys also receive supplementary food items, including a variety of fruits and vegetables, trail mix, and frozen treats, as well as foraging devices, which they can manipulate to obtain food. During the summer months, monkeys living in groups have access to pools and water enrichment.  Monkeys may also receive cognitive enrichment, including iPad apps and puzzle feeders.  


Another focus of the BSU is training. We work with clinical, husbandry, and scientific staff to train NHPs to voluntarily cooperate with procedures necessary for husbandry and research protocols, such as entering a transfer box or receiving an injection. We use positive reinforcement training (e.g., clicker training) in which animals get rewards for performing appropriate behaviors. Such training gives NHPs control over their environment, thereby reducing potential stress associated with the procedures.


The BSU staff at the ONPRC is committed to advancing our knowledge of how to increase the psychological wellbeing of our NHPs. We conduct research studies to examine behavioral management in an attempt to better understand psychological wellbeing issues. The results of these studies are presented at national and international meetings and published in scientific journals.

The Clinical Medicine Unit (CMU) is comprised of veterinarians and veterinary technicians committed to providing superior clinical and preventive veterinary care for nonhuman primates (NHPs) at the Oregon National Primate Research Center (ONPRC). The CMU team provides diagnosis and treatment for any medical conditions that may develop, and performs preventive care tasks, including annual physical examinations, weight management, and dental care. Our team delivers hundreds of medications daily, tailoring oral formulations according to the individual palates of our NHP patients. In addition, CMU performs a multitude of standard veterinary procedures just as would be done for our companion animals (e.g. x-rays; routine diagnostics such as obtaining blood, fecal, and urinary samples; intravenous fluid administration; and routine dental cleanings).

CMU oversees the health of all animals involved in research projects, which requires extensive communication with the scientists and research staff. Veterinarians provide veterinary and technical expertise to the scientists and the Institutional Animal Care and Use Committee (IACUC) during research protocol development, review, and modification. CMU staff continually seek methods to improve the health and welfare of the animals under their care. CMU staff work closely with the Behavioral Services Unit to ensure that the goals of NHP psychological well-being are met, and with ONPRC scientists and research staff to update procedures as new clinical standards of care emerge.

As is required both for maintaining licensure and to keep current with veterinary practice standards, technicians and veterinarians participate in regular continuing education events. Our technical staff are all involved in the American Association for Laboratory Animal Science (AALAS) certification process, attaining gradually higher certification levels as they progress in their careers. All veterinary technicians are professionally trained and certified with licensure from the State of Oregon. This includes participation in presentations at conferences, symposia, and outreach events, as well as publishing journal articles to share our knowledge with others. The veterinary staff provides teaching and mentoring to veterinary and technician students, research and husbandry staff, and many other entities on and off campus, to encourage understanding of research animal care and procedures throughout the biomedical research community. 

The Operations (Ops) Unit of the Division of Comparative Medicine (DCM) is responsible for ensuring the daily humane care of the nonhuman primates (NHPs) at the ONPRC. Operations develops and maintains exceptional facilities and performs husbandry and research support procedures in line with industry standard best practices. This unit also ensures the provision of excellent animal husbandry, outstanding technical expertise, and timely staff training for animal care and research personnel.

The Operations Unit is comprised of veterinarians, managers, supervisors, and animal care technicians who demonstrate a strong commitment and dedication to the care and well-being of our animals. DCM animal care technicians are the foundation of the animal care and research support program at the ONPRC. Membership in professional organizations, such as the American Association for Laboratory Animal Science (AALAS), is strongly encouraged and supported with the majority of our animal care staff certified at the various levels of AALAS technician certification. 

Some of the responsibilities of the Operations Unit include:

  • Providing daily husbandry, including feeding, enrichment and sanitization of the animals' environment. NHPs are fed a balanced diet, including fruit, vegetables, and forage twice daily.
  • Working closely with the Clinical Medicine Unit to conduct daily health observations on all animals every day.
  • Collaborating with the Behavioral Services Unit to develop and implement the animal enrichment program and to train animals to participate in research and husbandry tasks.
  • Providing research support services (e.g., preparing special diets for monkeys on specific research protocols.)
  • Working with the Education & Training Unit to provide training on proper laboratory animal husbandry and care.
  • Developing and maintaining facilities, equipment, and techniques for housing NHPs that promote their physical and psychological well-being (e.g., designing new cages to promote social housing of animals, expanding enrichment opportunities for indoor-housed animals.)
  • Ensuring that the ONPRC meets and exceeds various local, state and federal regulations and guidelines for the care and use of laboratory animals.
  • Developing, reviewing and revising Standard Operating Procedures and Guidelines for animal care and husbandry protocols.

Anatomic and clinical pathology expertise and services are key elements of the Oregon National Primate Research Center’s (ONPRC's) veterinary care program dedicated to the maintenance of self-sustaining populations of healthy, genetically characterized nonhuman primates (NHP) for research. They are also essential for meeting the objectives of our research programs. The Pathology Services Unit (PSU) provides diagnostic and surveillance services that promote the health and safety of ONPRC's animals. The PSU also provides research support services that strengthen the research program and contribute directly to the mission of the ONPRC. The PSU performs post mortem examinations, clinical pathology and microbiology services and interacts extensively with clinical veterinarians and investigators. The PSU administers a nonhuman primate (NHP) Tissue Distribution Program (TDP) to maximize the availability and use of these tissues and minimize the number of NHPs required for research. Databases for normal body and organ weights are maintained to advance research with NHPs, and pathology databases of spontaneous diseases are maintained to facilitate identification and characterization of NHP conditions potentially useful as animal models for biomedical research. Specialized training in NHP anatomic pathology is provided to students, fellows, and visiting scientists.  

Tissue Distribution Program

The Tissue Distribution Program is administered through the PSU. Tissues from NHPs are collected prospectively at the request of the recipient and according to the recipient's protocol. Off campus investigators typically receive fresh tissue shipped overnight or frozen tissues shipped within 10 days of collection. 

Inquires may be directed to Tissue Distribution

The Resources & Logistics (R&L) Unit of the Division of Comparative Medicine (DCM) is responsible for the management and health of nonhuman primate (NHP) breeding colonies, as well as oversight of short and long term NHP space and planning. R&L is comprised of veterinarians, laboratory, and administrative staff who demonstrate a strong commitment to the care and well-being of our animals and to enhancing biomedical research integrity. We coordinate across all units in the DCM, and with the five scientific divisions at the Oregon National Primate Research Center. Our three primary focus areas are Colony Management, Colony Health, and Research Facilitation.

Colony management integrates animal health and disease surveillance, breeding, and genetic programs to appropriately manage breeding colonies. We also project NHP colony growth and future research needs to ensure resources are available to investigators on a local, regional, and national basis.

Colony health ensures the production and maintenance of healthy animals by coordinating preventative and clinical care of all animals in the breeding colonies, as well as disease surveillance for all NHPs through the SPF surveillance laboratory.

Research facilitation supports optimal NHP biomedical research by providing data and resources to investigators during all stages of research, from grant submission, to selection and assignment of ideal NHP research models, including placing NHPs in optimal housing locations and providing electronic health record database entry and assistance.

The Surgical Services Unit (SSU) provides comprehensive surgical support for Oregon National Primate Research Center research programs and clinical medicine needs.

SSU responsibilities include pre-operative patient assessment and preparation, multimodal analgesia administration, anesthesia delivery, physiological monitoring, performing precise surgical procedures, patient anesthetic recovery, and complete post-operative care.  The SSU makes special efforts to conduct procedures using the least invasive means possible.  To accomplish this, we utilize state-of-the-art endoscopic and laparoscopic techniques as well as ultrasound, computed tomography, fluoroscopy, positron emission tomography and magnetic resonance imaging.  SSU staff members are professionally trained and certified, and share the Division of Comparative Medicine's common goal of promoting the optimum health and well-being of all research animals at the Center.