Histopathologic changes in laboratory animals resulting from various methods of euthanasia.

Area of Science:

• Veterinary Pathology
• Animal Research Methodology

Background:

• Histopathologic examination is crucial for understanding the effects of euthanasia on animal tissues.
• Selecting appropriate euthanasia methods is vital for research integrity and animal welfare.

Purpose of the Study:

• To investigate and compare the histopathologic changes induced by various euthanasia methods in common laboratory animals.
• To identify which euthanasia techniques are most suitable for specific post-mortem examinations, particularly of pulmonary and abdominal tissues.

Main Methods:

• Rats, mice, guinea pigs, and rabbits were subjected to different euthanasia protocols.
• Tissues were collected and examined histopathologically to identify and quantify lesions.
• Comparison of lesions across species and euthanasia methods was performed.

Main Results:

• Consistent histopathologic lesions were observed across species for each euthanasia method.
• All methods impacted lung tissues to varying degrees, including capillary congestion and pulmonary artery edema.
• Carbon dioxide (CO2) overexposure and intraperitoneal (ip) sodium pentobarbital injection showed suitability for pulmonary studies.
• Decapitation, cervical dislocation, CO2, and intracardial sodium pentobarbital injection were deemed suitable for abdominal viscera examination.

Conclusions:

• Euthanasia method significantly influences histopathologic findings, particularly in lung tissue.
• Specific methods, such as CO2 and sodium pentobarbital, are recommended for pulmonary research.
• Other methods like decapitation and cervical dislocation are better suited for abdominal organ analysis.