Introduction_to_the_Laboratory_Mouse_I_Aug_2024_Q

Introduction to Laboratory Mice

• Purpose: To provide an understanding of the basic biology and proper care of laboratory mice.

Origin and Strains

• Origin: Laboratory mice originated from Asia.

• Strain Development: Various strains with differing characteristics have been developed since their introduction into laboratories.

• Importance of Strain: Understanding the strain is vital for research and their care.

Types of Mice

• Outbred Mice:

  • Maintains genetic diversity.

  • Used for surrogate mothers, sentinel health monitoring, and population genetics modeling.

  • Obtainable from commercial suppliers and typically low cost.

• Inbred Mice:

  • Used for studying specific genotypic and phenotypic traits.

  • Requires systematic breeding to maintain genetic homozygosity.

Normative Data

• A table provides normative data for planning research experiments, essential for maintaining breeding colonies and cage density requirements.

• Standard operating procedures and guidelines exist for breeding mice.

Breeding and Colony Maintenance

• Control Breeding: Necessary to produce only required numbers for experiments and maintain colonies.

• Veterinary Support: Technical staff available for consultation.

• Development Chart of Mouse Pups: From birth to day 14; weaning must occur at 21 days of age. Smaller animals may need additional time with the mother.

Sexing and Housing

• Sexing: Should occur at or before weaning to prevent accidental mixing and litters.

• Housing:

  • Group Housing: Standard practice; single housing causes stress.

  • Cage Density: Avoid overcrowding, respect maximums for each cage type.

Behavior and Senses

• Mice exhibit nocturnal activity and have evolved to hide pain and distress due to being prey species.

• Sensory Development:

  • Born with poorly developed senses.

  • Develop acute smell and hearing; typically have poor eyesight, some strains may be genetically predisposed to blindness.

Health Indicators

• Signs of Health: A healthy mouse is alert, responsive, with a smooth coat and bright eyes.

• Clinical Signs of Illness: Detection of various health conditions is critical; refer to health conditions module.

• Reporting Illness: Sick mice should be reported to veterinary staff immediately.

Health Monitoring

• Sentinel Mice: Exposed to dirty bedding to detect infectious agents; these should not be moved or used for experiments.

Housing Conditions

• Caging: Lab mice are typically housed in shoebox cages with solid floors. Corn cob bedding is used to absorb waste and maintain hygiene.

• Environmental Enrichment: Essential for animal welfare; varies based on species needs.

Diet and Hydration

• Standard pelleted diet provided; special diets are the responsibility of investigative staff.

• Ensure continuous access to water through bottles or automatic systems.

• Always verify water access post-handling.

Stress Management

• Various stressors may affect health or research outcomes; strategies to minimize stress include:

  • Frequent habituation to handlers.

Documentation and Compliance

• Importance of maintaining accurate cage cards and documentation concerning surgeries and procedure details.

• Contact information must be current for emergency access to technical staff.

Reporting Concerns

• Always report concerns about animal care; anonymity is maintained in investigations.

• Responsibility in working with animals includes ethical and legal considerations.

Animal Welfare and Support

• Contact for Concerns: Reach out to veterinary technical staff or clinical veterinarians regarding animal welfare issues.

• Familiarization with animal use protocols and research regulations is crucial.