Research involving animals and animal welfare

The AO Research Institute Davos (ARI) conducts research to develop and evaluate new treatments, implants, and technologies in orthopedics and trauma care, aiming to enhance patient outcomes.

The ARI applies a range of research methodologies, including computer models, cell culture, bioreactors, and animal studies.

Currently, other research methodologies can’t fully replace animal research to investigate the multifactorial disorders of the musculoskeletal system. Additionally, regulatory bodies require animal research to ensure that treatment methods are safe for future human use.

The ARI is committed to conducting research involving animals only when scientifically and ethically justified, and when alternative methods are insufficient to answer a research question.

Legal and ethical framework

All animal research at the ARI is:

• conducted in accordance with Swiss animal welfare legislation
• reviewed and approved by cantonal authorities
• subject to regular inspections and oversight

Before approval, each study is assessed for:

• scientific necessity
• expected benefit
• animal welfare impact
• availability of alternatives
  
  
  

Commitment to transparency and the 3R principles

The ARI applies the 3R principles—replacement, reduction, and refinement—as a core requirement in the planning and conduct of all animal studies.

Replacement
Animal experiments are avoided wherever scientifically possible. The ARI actively uses and develops alternative methods, including laboratory based, computational, and biomechanical approaches.

Reduction
Studies are designed to use the minimum number of animals required to obtain reliable and meaningful results, supported by appropriate experimental design, statistical planning, and the use of analyses such as CT scans, which are non-invasive and allow measurements within the same animal over time.

Refinement
Procedures, housing, and handling are continuously refined to minimize pain, suffering, and distress and to support animal well-being throughout the study.

Transparency and public dialogue
The ARI supports the Swiss Transparency Agreement on Animal Research (STAAR). In line with this commitment, the ARI provides clear, contextualized information about why and how animal research is conducted.

Animals used in research

Where animal research is required, the ARI primarily works with:

• rodents (mice and rats)
• rabbits
• sheep, which are bred and cared for at the ARI’s own preclinical facility

Species selection is based on scientific relevance, ethical justification, and regulatory approval, with a preference for species with lower sentience whenever possible.

Animal care and welfare

Animal welfare is an integral part of research at the ARI. Measures include:

• species-appropriate housing and environmental enrichment
• continuous supervision by veterinarians specialized in laboratory animal medicine
• trained animal care and research staff
• ongoing monitoring of animal well-being

The ARI is part of the Swiss program of the European College of Laboratory Animal Medicine (ECLAM), which certifies specialists in laboratory animal medicine. The Diploma and Specialist titles are the highest qualifications for laboratory animal veterinarians in Europe.

Stephan Zeiter, the leader of the Preclinical Services Program (also an ECLAM specialist) received the Swiss Culture of Care Award in 2024, demonstrating the team's dedication to animal welfare.

All animal studies at the AO must be approved by the Cantonal Supervisory Commission for Animal Experimentation in Graubünden. A harm-benefit analysis is conducted to compare the harm and suffering animals might experience to the knowledge gained from the studies and their relevance for science and society. This limits animal studies to an indispensable minimum. The cantonal authorities also conduct regular inspections, both announced and unannounced, of the animal facilities at the ARI to ensure compliance with all applicable laws and licenses.

The ARI’s preclinical facility adheres to high standards that exceed legal requirements. It is certified according to ISO 9001:2015 and accredited by the Association for Assessment and Accreditation of Laboratory Animal Care (AAALAC). The AAALAC is a private, non-profit organization that promotes the humane treatment of animals in science through voluntary accreditation and assessment programs. It endorses the use of animals to advance medicine and science when no non-animal alternatives are available and when it is done in an ethical and humane way.

The ARI is also an officially recognized GLP test facility. GLP is an internationally recognized quality system for the organizational process and conditions under which non-clinical health and environmental safety studies are planned, performed, monitored, recorded, archived, and reported. All these accreditations demonstrate the ARI's commitment to meeting the highest research standards.

Use of sheep in preclinical research

When animal research is necessary, the ARI uses sheep as a large animal model in some preclinical studies because they provide scientifically relevant insights that cannot be obtained from smaller animal models alone.

Sheep are widely used in orthopedic research because they enable the evaluation of biomechanics, implant performance, and healing processes under conditions that better reflect clinical reality.

They have bone size, structure, and remodeling characteristics closer to those of humans than to those of rodents. This makes them a well-established model for studying bone healing and regeneration, fracture fixation, and orthopedic implants and biomaterials.

Sheep are used at the ARI only when a research question cannot be answered using alternative methods or smaller animal models. Their use is always subject to:

• ethical review
• legal approval
• application of the 3R principles
  
  
  

Specific pathogen free (SPF) sheep facility

As part of its preclinical infrastructure, the ARI operates a specific pathogen free (SPF) sheep facility.

“Specific pathogen free” refers to animals that are free of a defined list of pathogens that could otherwise:

• affect animal health and welfare
• interfere with research results
• introduce variability unrelated to the research question

SPF conditions are considered both a welfare measure and a scientific quality measure. SPF facilities are designed to prevent the introduction of these pathogens through controlled access, hygiene measures, and continuous health monitoring.

The SPF sheep facility was developed to meet an unmet need in Europe for pathogen-controlled large animal research while maintaining high animal welfare standards. 

Other animals at the ARI, like mice, rats, and rabbits, are obtained with SPF-status from certified breeders.

Euthanasia

In most preclinical studies at the ARI, animals need to be euthanized at the end of a study. This is never a routine decision and is taken only when it is scientifically justified, ethically approved, and legally required.

In orthopedic and musculoskeletal research, certain questions cannot be answered in living subjects. This includes the assessment of:

• bone–implant integration
• bone micro-  and macro-structure
• tissue responses at the implant or fracture site

Histological and biomechanical analyses—which require direct examination of bones and surrounding tissues—are often essential to validate healing, implant performance, and safety before clinical use. These analyses can only be performed after the animal has been humanely euthanized.

Euthanasia may also be necessary to prevent suffering at the conclusion of a study. In this context, euthanasia is considered part of responsible animal welfare practice. Whenever euthanasia is not necessary at the end of a study, efforts are made to rehome the animals.

Swiss frameworks explicitly recognize euthanasia as ethically permissible when justified by overriding scientific or animal welfare interests and when no alternative exists.