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Searching the Literature for Animal Testing Alternatives: A Tutorial: Step 2 : Keywords and The Question

Tutorial for researching alternatives to animal research

Created by Health Science Librarians

Step 2: Choosing Keywords to Form the Question

question markTo build your search, you must:

  1. Make a list of keywords specific to your research protocol
  2. Make a list of relevant keywords for the reduction, refinement, or replacement of animal research subjects (the "Three R's").

Record these keywords at the beginning of your literature search so that you are able to both be consistent across searches and provide the required narrative account of your literature search in your IACUC application. If you make changes or additions to your list of keywords as you search, include those changes in your records.

Protocol Specific Keywords

General Tips:

  • Scientific and common names of any species or model being studied
  • Scientific and common names of any diseases or conditions being studied
  • Generic name, trade names, and CAS RN of drugs and/or chemicals being used
  • Treatments being used
  • Scientific and common terms for tissues, systems, or cell lines being studied

Required Keyword Types:

  • Painful or distressing procedures in your protocol
    • Note: DO NOT attempt to use each in every search; you will run multiple searches.
  • Animal alternative searches (3Rs)

Suggested 3R Keywords for Searches

In addition to searching for research similar to your own, you will need to look for literature that mentions alternatives involving reduction, refinement, and replacement of animals in laboratory research. There are a lot of keywords that you can use to perform these searches, many of which are listed below. 

Reduction and Refinement

Analgesic, hypnotic, sedative, tranquilizer
Anesthesia, anesthesia, anaesthesia
Assay, technique, method, procedure
Enrichment (behavioral, behavioural, environmental)
Experimental design
Handling, housing, husbandry, caging
          Invasive, non-invasive
Monitoring device
Positive reinforcement
Postoperative, postsurgery
Reduction, refinement
Restraint, restrict, immobilize
Train, educate, teach, instruct
Welfare, pain, stress, distress


          Algae, fungus, hydra, plant
Anesthesia, anesthesia, anaesthesia
Animal testing alternatives, alternative
Artificial intelligence system, AI
Assay, technique, method, procedure
Autopsy, biopsy
Bacteria, microorganism, protozoan, single-celled organism, yeast
Cell, cell line, cellular
Computer aided instruction, computer assisted instruction, CAI
Culture (cell, tissue, organ)
Digital imaging
Environmental enrichment
Fish, cephalopod
Insect, invertebrate
          Isolated (cell, tissue, organ)
Mannequin, manikin, manikin
Membrane, organ, organelle, slice, tissue, tissue equivalent
Model (animal, cadaveric, interactive, mathematical, statistical, theoretical), modelling, modeling
Pain, distress
Physicochemical systems
Replacement, surrogate
Simulation (computer)
Structure - activity relationship
Train, educate, teach, instruct
Virtual (surgery, reality)
Vitro (AND method, model, technique)

Sample Animal Alternatives MeSH Keywords & Searches for PubMed MEDLINE

When searching PubMed or one of the other MEDLINE interfaces, it is often a good idea to use the Medical Subject Headings (MeSH) to find relevant articles. MeSH headings are assigned to each article within MEDLINE by its staff and are intended to be consistent across articles. This allows them to return more relevant and consistent groups of articles when searched.

PubMed provides a searchable MeSH Database to help you identify the best terms for your search, which includes many that apply to a literature search for alternative research methods in animal studies.

If you use a MeSH term, you must tell PubMed that you want it to be a MeSH term and not something else in order to find the most relevant results. To do this, type the term inside quotation marks followed by [MESH].  See below for examples. 

Sample standard MeSH keywords (click on the keyword to see the MeSH definition, if available):

          "Animal Testing Alternatives"[MESH]
"Animals, Laboratory"[MESH]
"Animal Husbandry"[MESH]
"Animal Welfare"[MESH]
""Euthanasia, Animal""[MESH]
          "Housing, Animal"[MESH]
"Investigative Techniques"[MESH]
"Laboratory Animal Science"[MESH]
"Models, Animal"[MESH]
"Research Design"[MESH]

Using MeSH Terms

MeSH terms can be combined to produce generalized searches for major topics in animal testing, including the health, welfare, and housing of animal subjects. Listed below are some sample searches for major issues of interest in your literature search.  

Blood Sampling: ("Blood Specimen Collection/methods"[Mesh]) AND ("Animals, Laboratory"[Mesh])

Housing, Including Cages and Caging: ("animal husbandry"[MESH] OR "animal welfare"[MESH] OR "housing, animal"[MESH]) AND "animals, laboratory"[MESH] AND (caging OR cage* OR "housing, animal"[MESH])

Environmental Enrichment: "animals, laboratory "[MESH] AND enrichment[Text Word] AND "housing, animal"[MESH] 

Laboratory Animal Welfare: "animal welfare"[MESH] AND "animals, laboratory "[MESH]) 

Transgenic Mice: "mice, transgenic"[MESH] AND ("animal welfare"[MESH] OR "Animal Testing Alternatives"[MESH]) 

Pain and/or Stress Prevention and Control: ("stress, physiological/prevention and control"[MESH] OR "pain/prevention and control"[MESH] OR "stress, physiological/veterinary"[MESH] OR pain/veterinary"[MESH]) AND "animal welfare"[MESH] AND ("animals, laboratory"[MESH] OR "research design"[MESH]) 

Handling: "animals, laboratory"[MESH] AND "animal husbandry"[MESH] AND ("handling (psychology)"[MESH] OR handling[Text Word]) 

Alternative Searching Resources

You are required to use keywords that relate to alternatives to animal research procedures, specifically focused on the 3 R's, reduction, replacement, and refinement.  Some of them will be more relevant to your specific research proposal than others; be sure to choose carefully.