A quantitative swab is a good non-invasive alternative to a quantitative biopsy for quantifying bacterial load in wounds healing by second intention in horses.

This research aims to assess different techniques to diagnose wound infections in horses, particularly wounds healing by a process called second intention. The study finds that a quantitative swab method is a reliable, non-invasive alternative to a quantitative biopsy for measuring bacterial load in such wounds.

Objective of the Study

• The study aimed to compare various available methods for diagnosing infections in equine wounds that are healing by a process known as “second intention”. These methods included clinical assessment, quantitative swab, semi-quantitative swab, and a swab for cytology. The findings from these methods were compared with results from a quantitative tissue biopsy, which served as a reference standard in this case.

Methodology

• A total of 50 wounds that were healing by second intention were assessed using the methods mentioned above. Further, a part of the biopsy specimen was also examined histologically to check for the presence of a biofilm, which is a layer of bacteria that can form on wound surfaces.
• Furthermore, a few specimens with biofilms were subjected to a vortex and sonication protocol; this was done to release bacteria from the biofilm, and assesses the effect on quantitative bacteriology.

Findings

• The study found a high correlation between the results of the quantitative swabs and the quantitative biopsies, indicating that the swab method could accurately represent the bacterial load in the wounds.
• Results from semi-quantitative swabs also showed a moderate correlation with the biopsies.
• It was observed that higher white blood cell counts were significantly associated with lower bacterial counts in the wounds. Additionally, wounds with black granulation tissue showed higher bacterial counts.
• The vortex and sonication protocol did not result in higher bacteriological counts in specimens with biofilms, indicating that this technique may not be effective in biofilm cases.

Conclusion

• Based on its findings, the study concludes that a quantitative swab is an acceptable non-invasive alternative to a quantitative biopsy for determining bacterial load in wounds of horses healing by second intention.