Refinement & Enrichment Advancements Laboratory

White pair-housed male rabbitsThe University of Michigan is home to one of the nation’s first and only programs dedicated to optimizing biomedical research efforts through improved animal well-being by understanding the intersection of the animal’s lived experience and the scientific results.

Established in 2014 by ULAM Faculty Veterinarians Jennifer Lofgren DVM, MS, DACLAM and Jean Nemzek, DVM, MS, DACVS, the Refinement & Enrichment Advancements Laboratory (REAL) is comprised of laboratory animal veterinarians, veterinary technicians, animal care staff, and scientists dedicated to providing expertise and collaboration to colleagues interested in refining their animal models(s) and/or animal care.

REAL has collaborated with scientists in the Department of Surgery and Anesthesiology, as well as veterinarians at Michigan State University and Wayne State University. As a laboratory, they have received three Cohen Clinical Research Awards, three American College of Laboratory Animal Medicine (ACLAM) Foundation grants, and four AALAS Grants for Laboratory Animal Science (GLAS) grants.

REAL achieves its mission through utilizing the scientific method to evaluate both animal welfare and scientific outcomes. In both past and present studies, REAL has validated advancements in enrichment and refinements to produce scientifically-sound recommendations for improved animal care and use. 

Areas of Research

  • Carcass degradation rates to determine how long carcass tissue is viable for some research needs to facilitate reduction in animal use
  • Humane endpoints for aged rats to facilitate earlier study endpoints
  • Novel behavioral ethograms validated for identification of post-castration and post-spay pain in guinea pigs
  • Novel touch pad technology to identify post-surgical pain in peripheral ischemic injury and deep vein thrombosis (DVT) models in mice
  • Novel nest consolidation and grooming tests for assessment of post-laparotomy pain in mice
  • Feline ethogram to recognize illness behaviors prior to development of clinical signs in vaccine study
  • Tramadol and buprenorphine on sepsis models
  • Robenacoxib, carprofen, and low dose buprenorphine on DVT model
  • Multimodal vs single analgesic agent therapy for post-castration and post-spay pain guinea pigs
  • Extended release buprenorphine for prevention of post-spay pain in guinea pigs
  • Multimodal vs single analgesic therapy for prevention of post-laparotomy pain in mice
  • Analgesia efficacy of oral carprofen in mice
  • Pharmacokinetics of extended release buprenorphine in pigs
  • Pharacokinetics of transdermal fentanyl in sheep
  • Evaluation of room air as a carrier for isoflurane instead of 100% oxygen
  • Preference testing of mice for a variety of novel and commercially available nesting materials
  • Epidemiological evaluation of whether presence of a nest interferes with identifying mice in need of veterinary attention
  • Use of 3D modeling to assess nest volume
  • Identifying which nesting material provides greatest benefit for rabbit kit survival
  • Feline preference testing for environmental enrichment items
  • Rabbit social behavioral ethogram to identify what behaviors predict pair failure
  • Using increased monitoring and enrichment as interventions to increase success of pair maintenance


REAL is also interested in supporting the education and training of laboratory animal stakeholders (e.g., scientists, students, veterinarians, and veterinary technicians) with an interest in the improvement of laboratory animal welfare. Those interested in learning more about animal enrichment are encouraged to review the following resources:


  • Novel methods of cageside evaluation of post-surgical pain in mice
  • Evaluation of analgesia efficacy for prevention of post-operative pain in mice
  • Interventions and methods of improving rabbit social housing success
  • Which Nest is Best? A Study to Harmonize the Happiness of Both Mouse and Animal Care Technician (AALAS 2013)
  • Determination of an Effective Tramadol Dose in a Murine Model of Abdominal Surgery and Inflammation (AALAS 2013)
  • Presence of Nesting Material Does Not Prevent Ability To Accurately Identify Sick or Dead Mice During Routine Health Checking (AALAS 2014)
  • Validation of a Novel Behavioral Ethogram for Identification of Post-operative Pain in the Guinea Pig (Cavia porcellus) (AALAS 2014)
  • A Novel TouchPad Application As A Functional Tool for Gait Assessment: A Pilot Study Using a Murine Hindlimb Ischemia Model (AALAS 2014)
  • Behavioral Ethograms as a Health Assessment Tool in a Feline Vaccine Study (AALAS 2014)
  • Benefits of 21% O2 Compared with 100% O2 for Isoflurane Delivery to Mice (AALAS 2014)
  • Concentration Impacts Analgesic Efficacy of Tramadol in Mice (AALAS 2014)
  • Troubleshooting Aggressive Behaviors in Pair-Housed Rabbits Using Environmental Enrichment (AALAS 2015)
  • Large Nests Do Not Interfere with the Ability to Identify Sick or Dead Mice (AALAS 2015)
  • Postoperative Analgesic Efficacy in the Male Guinea Pig (Cavia porcellus) (AALAS 2015)
  • Novel Methods of Evaluation of Postsurgical Pain in Female Guinea Pigs (AALAS 2015)
  • Digital Modeling as a Novel Approach to the Analysis of Mouse Nests (AALAS 2015)
  • Comparison of Rolled Paper to Crinkle Paper as Enrichment for C57BL/6J Mice (AALAS 2015)
  • Microfluidic Alternatives to Animal Research (AALAS 2015)
  • Modifying Rabbit Anesthesia for Increased Surgical Duration (AALAS 2015)
  • Which Nest Is Best? Nesting Material Improves NZW
  • Transgenic Rabbit Breeding Colony Kit Survival Rates (AALAS 2016)
  • Novel Cageside Methods for Recognizing Unalleviated Postoperative Pain in Mice (AALAS 2016)
  • Evaluation of Analgesia Efficacy in a Guinea Pig (Cavia porcellus) Surgical Pain Model (AALAS 2016)
  • The Effects of Socialization and Playtime on Antibody Production in Long-Term, Single-Housed New Zealand White Rabbits (AALAS 2016)

Affiliated Faculty​


If you would like to know more about REAL, or are interested in learning about how animal enrichment can enhance your next project, please contact or call (734) 764-0277.