A pilot study on ethanol-polyethylene glycol-formalin fixation of farm animal cadavers.

This research study examines the use of a new embalming solution that results in more naturally appearing farm animal cadavers for teaching veterinary anatomy. The technique uses lower concentrations of formaldehyde, in combination with ethanol and polyethylene glycols, and was qualitatively assessed for its effectiveness in preserving the specimens while minimizing health and safety risks.

Research Methodology

• The research project used the cadavers of sheep, horses and calves to test a fixation (embalming) solution containing reduced formaldehyde concentrations (2% and 3%), together with ethanol and polyethylene glycols.
• The fixation solution was tested over two months for sheep, and three months for horses and calves, with twice-weekly dissections to assess: the ‘palpable consistency’ (feel of the tissue), flexibility, colour, tissue hydration and odour of the specimens. These aspects were evaluated qualitatively, meaning they were assessed based on observation and description rather than structured measurement.
• The formaldehyde levels present in the ‘breathing zone’ (the area of air from which a person would typically breathe) around the cadavers were measured to determine potential health and safety risks.
• To evaluate how well the solution prevented microbial growth, tissue samples were analyzed for the presence of culturable aerobic and anaerobic bacteria, yeasts and moulds.

Research Findings

• Formaldehyde exposure was found to be under the maximum allowable concentration for all but one specimen, a 300 kg horse cadaver. This implies the solution could be safer than traditional methods which use higher concentrations of formaldehyde and pose more significant health risks.
• In terms of preserving the specimens, the solution seemed to be reasonably effective. The samples retained a natural appearance, with satisfactory results in terms of the assessed factors of consistency, flexibility, colour, hydration and odour.
• However, the embalming solution was not entirely successful in preventing microbial growth. Several types of bacteria were isolated from a lung sample, and Micrococcus sp. and Bacillus sp. from a muscle sample. This suggests that the solution may need further refinement to improve its antimicrobial properties.

Significance and Implications

• The research provides an initial investigation into an alternative embalming solution for veterinary teaching specimens, which successfully reduces formaldehyde concentration while maintaining a natural specimen appearance.
• This could have implications for both improving the quality of veterinary anatomy education and reducing health risks related to formaldehyde exposure.
• Further research is required to enhance the embalming solution’s antimicrobial properties or to explore additional ways to prevent microbial growth following embalming.